Each year, all final year students take a mathematics exam. It is hypothesised that the population mean score for this test is 80. It is known that the population standard deviation of test scores is 13. A random sample of 23 students take the exam. The mean score for this group is 71. a)Calculate the 90% confidence interval for the population mean test score. Give your answers to 2 decimal places.

Answers

Answer 1

Answer:

The 90% confidence interval for the population mean test score is between 66.54 and 75.46.

Step-by-step explanation:

We have that to find our \(\alpha\) level, that is the subtraction of 1 by the confidence interval divided by 2. So:

\(\alpha = \frac{1 - 0.9}{2} = 0.05\)

Now, we have to find z in the Ztable as such z has a pvalue of \(1 - \alpha\).

That is z with a pvalue of \(1 - 0.05 = 0.95\), so Z = 1.645.

Now, find the margin of error M as such

\(M = z\frac{\sigma}{\sqrt{n}}\)

In which \(\sigma\) is the standard deviation of the population and n is the size of the sample.

\(M = 1.645\frac{13}{\sqrt{23}} = 4.46\)

The lower end of the interval is the sample mean subtracted by M. So it is 71 - 4.46 = 66.54

The upper end of the interval is the sample mean added to M. So it is 71 + 4.46 = 75.46

The 90% confidence interval for the population mean test score is between 66.54 and 75.46.


Related Questions

NEED help . !!!! Don’t understand this

NEED help . !!!! Dont understand this

Answers

Step-by-step explanation:

multiply 8 and the -3r + 7

8(-3r + 7 )

-24r + 56 is the area :)

a box contains four tickets, one marked with a star, and the other three blank: Two draws are made at random with replacement from this box. What is the chance of getting a blank ticket on the first draw. What is the chance of getting a blank ticket on the second draw

Answers

the first draw is a 75% chance and the second would be a 67%

PLEASE HELP AS SOON AS POSSIBLE

PLEASE HELP AS SOON AS POSSIBLE

Answers

A) The Slope is: 2

B) The interpretation of the slope is that there are two races for each number of track meet.

C) The y-intercept from the graph is at: y = 4

D) Equation of the line is: y = 2x + 4

How to find the slope of the linear graph?

The general form of equation of a line in slope intercept form is:

y = mx + c

where:

m is slope

c is y-intercept

From the given graph, we can see that the slope is gotten from the formula:

A) Slope = (y₂ - y₁)/(x₂ - x₁)

Thus:

Slope = (10 - 4)/(3 - 0)

Slope = 6/3

Slope = 2

B) The interpretation of the slope is that there are two races for each number of track meet.

C) The y-intercept from the graph is at: y = 4

D) Equation of the line is:

y = 2x + 4

Read more about Slope at: https://brainly.com/question/3493733

#SPJ1

sorry forgot to add a photo to the ones who answered my other one

sorry forgot to add a photo to the ones who answered my other one

Answers

Answer:

Step-by-step explanation:

8.5x16=136

Find f′(x)
1. f(x) = x + 2
2. f(x) =2/x2

Answers

f'(x) = 0 * x^(-2) + (-2/x^3) = -2/x^3.

So, the derivative of f(x) = 2/x^2 is f'(x) = -2/x^3.

To find f'(x) for the function f(x) = x + 2, we can use the power rule for derivatives.

The power rule states that if we have a function of the form f(x) = x^n, then the derivative is given by f'(x) = n*x^(n-1).

In this case, the function f(x) = x + 2 can be written as f(x) = x^1 + 2.

Applying the power rule, we differentiate each term separately:

f'(x) = d/dx (x^1) + d/dx (2)

The derivative of x^1 is 1x^(1-1) = 1x^0 = 1.

The derivative of a constant term like 2 is 0, as the derivative of a constant is always 0.

Therefore, f'(x) = 1 + 0 = 1.

So, the derivative of f(x) = x + 2 is f'(x) = 1.

To find f'(x) for the function f(x) = 2/x^2, we can use the power rule and the constant multiple rule.

The power rule states that if we have a function of the form f(x) = x^n, then the derivative is given by f'(x) = n*x^(n-1).

The constant multiple rule states that if we have a function of the form f(x) = cg(x), where c is a constant, then the derivative is given by f'(x) = cg'(x), where g'(x) is the derivative of g(x).

In this case, the function f(x) = 2/x^2 can be written as f(x) = 2 * x^(-2).

Applying the power rule and the constant multiple rule, we differentiate each term separately:

f'(x) = d/dx (2 * x^(-2))

Applying the constant multiple rule, the derivative of 2 is 0, as it is a constant term.

Applying the power rule, the derivative of x^(-2) is (-2) * x^(-2-1) = (-2) * x^(-3) = -2/x^3.

for more question on derivative

https://brainly.com/question/28376218

#SPJ8

FASTEST GETS MOST POINTS
a tuxedo rental service charges $150 flat fee for a suit plus $50 per additinal day. The total cost of the tuxedo is $300. How many days was the tuxedo rental for?

Answers

The tuxedo was rented for 4 days.

Let's start by assigning variables to the unknowns. Let "x" be the number of additional days rented, and "d" be the total number of days rented (including the first day).

From the given information, we know that the flat fee for the rental is $150, so the cost of the additional days is the total cost minus the flat fee, which is $300 - $150 = $150. We also know that the cost for each additional day is $50. Therefore, we can set up the equation:

$150 + $50x = $300

Subtracting $150 from both sides, we get:

$50x = $150

Dividing both sides by $50, we get:

x = 3

So the tuxedo was rented for 3 additional days, making the total number of days rented:

d = 1 + 3 = 4

To learn more about rented here:

https://brainly.com/question/16489690

#SPJ1

What is the surface area of the triangular prism???
I really need an answer to this. My math test is tomorrow and I really need to be prepared!

What is the surface area of the triangular prism???I really need an answer to this. My math test is tomorrow

Answers

The surface area of the triangular prism is B. 1,008 \(cm^{2}\)

What is Triangular Prism?

Triangular Prism is a polyhedron made up of two triangular bases and three rectangular sides. It is a three-dimensional shape that has three side faces and two base faces, connected to each other through the edges.

How to determine this

The surface area of the triangular prism =  Area of the front Triangle + Area of the triangle + Each sides of the triangle by the length of the triangular prism.

Area of the front and back triangle will be the the same given the same base and height

To find the area of the triangle = 1/2 * Base * Height

Where base = 12 cm

Height = 9 cm

Area = 1/2 * 12 cm * 9 cm

Area = 6 * 9 \(cm^{2}\)

Area of the one triangle = 54 \(cm^{2}\)

So, by multiplying each sides of the triangle by the length

= Base * Length

= 12 cm * 25 cm

= 300\(cm^{2}\)

Height * Length

= 9 cm * 25 cm

= 225 \(cm^{2}\)

Then, Hypotenuse * Length

= 15 cm * 25 cm

= 375 \(cm^{2}\)

Surface area = 54\(cm^{2}\) + 54\(cm^{2}\) * 300\(cm^{2}\) + 225\(cm^{2}\) + 375\(cm^{2}\)

Surface Area = 1,008\(cm^{2}\)

Read more about Triangular prism

https://brainly.com/question/30739454

#SPJ1

Select the sketch of the right rectangular prism with height of 2cm and bases that are 5 cm by 3 cm.

Answers

Answer: See image

Step-by-step explanation:

The bases are 5cm times 3cm, meaning that 2 parallel sides have to be 5cm by 3cm, 2 other parallel sides have to 2cm by 3cm, and the 2 other parallel sides have to be 5cm by 2cm.

Select the sketch of the right rectangular prism with height of 2cm and bases that are 5 cm by 3 cm.

Suppose P(x) = 3x 2−4x−7 is a quadratic function and we suspect that 8 3 is a zero of P(x). How can we confirm our suspicion?

Answers

P(8/3) is not equal to zero, we can conclude that 8/3 is not a zero of P(x). Therefore, our suspicion was incorrect.

What is quadratic equation and how to solve it ?

A quadratic equation is a second-degree polynomial equation of the form ax^2 + bx + c = 0, where a, b, and c are constants and x is the variable.

To solve a quadratic equation, there are different methods, such as factoring, completing the square, and using the quadratic formula. The quadratic formula is the most general method and can be used for any quadratic equation.

It states that the solutions to the equation ax^2 + bx + c = 0 are given by the formula

x = (-b ± sqrt(b^2 - 4ac)) / (2a).

We can use this formula to find the roots of the equation by substituting the values of a, b, and c into the formula and simplifying.

To confirm if 8/3 is a zero of the quadratic function P(x) = 3x^2 - 4x - 7, we can substitute 8/3 for x in the equation and check if the resulting expression is equal to zero. If P(8/3) equals zero, then we can confirm that 8/3 is indeed a zero of P(x).

P(8/3) = 3(8/3)^2 - 4(8/3) - 7

= 3(64/9) - 32/3 - 7

= 64/3 - 32/3 - 21/3

= 11/3

Since P(8/3) is not equal to zero, we can conclude that 8/3 is not a zero of P(x). Therefore, our suspicion was incorrect. If we want to find the zeros of P(x), we can use the quadratic formula or factor the equation into (3x + 1)(x - 7) = 0 to get the roots x = -1/3 and x = 7.

To know more about Quadratic equation visit:-

https://brainly.com/question/1214333

#SPJ1

What values of x
and y
satisfy the system of equations {8x+9y=−36 x+7y=1}

Enter your answer as an ordered pair, like this: (42, 53)

If your answer includes one or more fractions, use the / symbol to separate numerators and denominators. For example, if your answer is (4253,6475),
enter it like this: (42/53, 64/75)

If there is no solution, enter "no"; if there are infinitely many solutions, enter "inf."

Answers

The solution to the system of equations is (x, y) = (-261/47, 44/47) as an ordered pair.

To solve the given system of equations:

Equation 1: 8x + 9y = -36

Equation 2: x + 7y = 1

We can use the method of substitution or elimination to find the values of x and y. Let's use the method of substitution:

From Equation 2, we can solve for x:

x = 1 - 7y

Substituting this value of x into Equation 1:

8(1 - 7y) + 9y = -36

8 - 56y + 9y = -36

-47y = -44

y = 44/47

Substituting the value of y back into Equation 2 to find x:

x + 7(44/47) = 1

x + 308/47 = 1

x = 1 - 308/47

x = (47 - 308)/47

x = -261/47

Therefore, as an ordered pair, the solution to the system of equations is (x, y) = (-261/47, 44/47).

Learn more about system of equation on:

https://brainly.com/question/12526075

When she flew to Indiana, her flight said it was 42% full. Does that mean 42 people were on the plane?

Answers

Answer:

No, 42% means that for every 100 seats in the plane, 42 were occupied.

Explanation:

No, 42% means that for every 100 seats in the plane, 42 were occupied. So, if for example, the plane has a capacity of 500 seats, we can calculate the number of people in the plane as:

500 x 42 / 100 = 210

So, if the plane has 500 seats and it was 42% full. It means that 210 of them were occupied.

Find the magnitude and direction of the vector using the given information. V=<6,7>

Find the magnitude and direction of the vector using the given information. V=&lt;6,7&gt;

Answers

Answer:

The magnitude of the vector is 9.165 and it's direction is 40.6°

Step-by-step explanation:

Vector Quantities:

A vector quantity is a quantity that has both size (magnitude) and direction. Examples of vector quantities are force, velocity and impulse.

Magnitude of vector v is given by

|v| = √6²+7²

= √36+49

= √84

= 9.165

Direction of vector v is obtained by:

\( \tan( \theta) = \frac{x}{y} \)

\(\theta = {tan}^{ - 1} ( \frac{6}{7}) \)

\(\theta = {40.6°}\)

Learn more about vector quantities from: https://brainly.in/question/3437975

#SPJ1

Greg has 4 shirts: a white one, a black one, a red one, and a blue one. He also has two pairs of pants, one blue and one tan. What is the probability, if Greg gets dressed in the dark, that he winds up wearing the white shirt and tan pants? Show your work. (10 points)
MARKING BRINLIEST AND GIVING A LOT OF POINTS PLSSSS HELP

Answers

The probability, if Greg gets dressed in the dark, that he winds up wearing the white shirt and tan pants is 0.125 or 12.5%.

To find the probability that Greg winds up wearing the white shirt and tan pants while getting dressed in the dark, we need to find out all the possible outfit options. According to the question given, first we nned to find out number of outfit combinations possible.

Total number of Outfit Combinations:

There are 4 shirts: a white one, a black one, a red one, and a blue one and also two pairs of pants, one blue and one tan. So, total number of possible outfit combinations would be 4 * 2 = 8.

No of favourable options:

As given in the question, Greg wears white shirt and tan pants. There is only one white shirt and one tan pant. So, number of favourable options would be only 1 .

Probability = Number of favourable outcomes/Total no. of combinations

Probability = 1/8

Probability = 0.125 or 12.5%

Therefore, the probability, if Greg gets dressed in the dark, that he winds up wearing the white shirt and tan pants is 0.125 or 12.5%.

To study more about Probability:

https://brainly.com/question/13604758

https://brainly.com/question/251701

What is the volume of the following rectangular prism. Help please!

What is the volume of the following rectangular prism. Help please!

Answers

Answer: \(7\frac{2}{3} units^{3}\)

Step-by-step explanation:

Volume=lwh

Volume=23/4(4/3)

Volume=92/12

Volume=7 8/12

Volume=7 2/3

Find the probability of rolling divisors of 24

Answers

Answer:

5/6 is the probability

Step-by-step explanation:

Factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24 and rolling a 6-sided die you can get 1, 2, 3, 4, 5, 6 so 5 is the only thing you can roll that isn't a factor of 24 so

a function is defined by the equation f(1/2)=2X-5

Answers

Answer:

The value of f(-1) in the given equation is -10.

Step-by-step explanation:

When we see f(-1), it means that -1 is represented as our value of x. So, knowing this information, we can plug this into our given equation.

f(-1) = -3(-1)² + 2(-1) - 5

Simplify the exponent on -1.

f(-1) = -3(1) + 2(-1) - 5

Multiply -3 by 1.

f(-1) = -3 + 2(-1) - 5

Multiply 2 by -1.

f(-1) = -3 - 2 - 5

Subtract 2 from -3.

f(-1) = -5 - 5

Subtract 5 from -5.

f(-1) = -10

What is the approximate area of the shaded region? Use 3.14 for 7.
1 in
6 in
4 in
A. 23 square inches
B. 27.14 square inches
C. 22.43 square inches
OD. 20.86 square inches

Answers

The Area of the shaded region is 20.86 in²

What is the area of circle?

The area of a circle is calculated using the formula A = πr², where "A" is the area of the circle.

We know,
Area of Rectangle = l × w,      where l = length and w = width
Area of Circle = \(\pi r^{2}\),                where r = radius.

find the area of the rectangle,
length = 6 in and width = 4 in
Area of Rectangle = 6 × 4 = 24 inch²

Here given the circle radius is 1 inch, and we use π as 3.14

Area of Circle = \(\pi r^{2}\)
Area of Circle = 3.14 × 1² = 3.14 in²  

The area of the shaded region as per figure below is:

Area of the shaded region = Area of Rectangle - Area of Circle

Area of the shaded region = 24 - 3.14 = 20.86 in²

Therefore, the answer is D.  20.86 square inches.

To know more about area of circle, visit:

https://brainly.com/question/10645610

#SPJ1

What is the approximate area of the shaded region? Use 3.14 for 7.1 in6 in4 inA. 23 square inchesB. 27.14

someone please answer this its confusing me

someone please answer this its confusing me
someone please answer this its confusing me

Answers

24. opposite sides of a parallelogram are always congruent

the line AB will be congruent to line DC so 8t + 7 = 9t - 2 which gives you t = 9

line AD will also be congruent to line BC so 4s + 1 = 2s + 25 which gives you s = 12

Find the difference of the complex numbers.
(7 +3i)-(3-7i)
O A. 4 + 10i
O B. 10-4i
O C. 4- 4i
O D. 10 + 10i

Answers

Answer:

A) 4+10i

Step-by-step explanation:

(7+3i)-(3-7i)

7+3i-3-(-7i)

7+3i-3+7i

7-3+3i+7i

4+3i+7i

4+10i

4. Which of the following represents a function?
(8,3), (8,3), (-8, -3), (-8, -3)
0 (-5, 6), (-5, 6), (-5, -6), (-5, -6)
O (3,9), (-7, 1), (6, 12), (-3, -9)
O (5, 1), (5,2), (5, 3), (5, 4)

Answers

The 3 option
(3,9), (-7,1), (6,12), (-3, -9)

Help me please. I don't know what to do or where to start.

Help me please. I don't know what to do or where to start.

Answers

The number of cars in the parking lot at 5 pm is 106.1.

The formula for the number of cars in the parking lot n hours after 3 pm is:

\(A_{n} = 92(1.09)^n\)

where:

\(A_{n}\) is the number of cars in the parking lot n hours after 3 pm

92 is the initial number of cars in the parking lot

1.09 is the growth rate of the number of cars in the parking lot

n is the number of hours after 3 pm

For example, if it is 5 pm, then n = 2. Plugging this value into the formula, we get:

\(A_{5} = 92(1.09)^2\)

\(A_{5} = 106.1\)

Therefore, the number of cars in the parking lot at 5 pm is 106.1.

For such more question on number:

https://brainly.com/question/30752681

#SPJ8

WHAT 271,403 ROUNDED TO HUNDRED

Answers

Answer:

271,400

Step-by-step explanation:

I hope this helps

PLEASE HELP
The table of values represents an exponential function.

What is the y-coordinate of -3f(x-1) when x = 0
Enter your answer in the box.
SEE PHOTO

PLEASE HELPThe table of values represents an exponential function.What is the y-coordinate of -3f(x-1)

Answers

The y-coordinate of -3f(x-1) when x = 0 is -63

What is the y-coordinate of -3f(x-1) when x = 0

From the question, we have the following parameters that can be used in our computation:

The table of values

So, we have

-3f(x - 1)

When x = 0, we have

y = -3f(0 - 1)

This gives

y = -3f(-1)

From the table, we have

y = -3 * 21

Evaluate

y = -63

Hence, the y-coordinate is -63

Read more about exponential function at

https://brainly.com/question/2456547

#SPJ1

An economy is operating with output $400 billion above its natural level, and fiscal policymakers want to close this expansionary gap. The central bank agrees to adjust the money supply to hold the interest rate constant, so there is no crowding out. The marginal propensity to consume is 3/4, and the price level is completely fixed in the short run.

to close the expansionary gap, the government would need to increase or decrease spending by $ billion.

Answers

Hence, to close the expansionary gap, the government would need to decrease spending by $100 billion.

To close the expansionary gap, the government would need to decrease spending by $100 billion.

The formula to calculate the change in equilibrium output due to a change in government spending is:

∆Y = (∆G / (1 - MPC))

Where:

∆Y = change in equilibrium output

∆G = change in government spending

MPC = marginal propensity to consume

Here, the output is $400 billion above its natural level, and the central bank agrees to adjust the money supply to hold the interest rate constant, so there is no crowding out. Therefore, we can assume that the change in government spending (∆G) would have a one-to-one effect on the equilibrium output (∆Y).

Given that MPC = 3/4, we can plug in the values into the formula:

400 = (∆G / (1 - 3/4))

∆G = (1 - 3/4) * 400

∆G = (1/4) * 400

∆G = 100

Hence, to close the expansionary gap, the government would need to decrease spending by $100 billion.

To know more about interest rate visit:

https://brainly.com/question/14445709

#SPJ1

Choose the equation that
matches the graph.
(¹)* -
a.
y =
b. y = 4x-1
-4
X-4
c. y = (-²)*
d.
e.
y = 4* + 1
y = 4x+1
Enter

Choose the equation thatmatches the graph.()* -a.y =b. y = 4x-1-4X-4c. y = (-)*d.e.y = 4* + 1y = 4x+1Enter

Answers

The equation y = 4x-1 matches the graph, which has a slope of 4 and a y-intercept of -1. This is because the coefficient of x is 4 (slope) and the constant term is -1 (y-intercept).

What is the slope of a line?

A line's slope is a measure of how steeply it rises or falls as it goes from left to right on a coordinate plane. It is defined as the shift in vertical coordinate (y) to horizontal coordinate (x) between any two locations on a line. The slope (m) may be written symbolically as:

m = (change in y) / (change in x)

Positive, negative, zero, or undefined slopes are all possible. A horizontal line has a slope of zero, while a vertical line has an indeterminate slope.

Based on the given options, the equation that matches the graph is:

b. y = 4x-1

This is because the graph has a slope of 4 (meaning it increases by 4 units in the y-direction for every 1 unit in the x-direction), and a y-intercept of -1 (meaning the line crosses the y-axis at -1). This matches the equation y = 4x-1, where the coefficient of x is 4 (slope) and the constant term is -1 (y-intercept).

To know more about slope, visit

brainly.com/question/14511992

#SPJ1


In a particular triangle, the second side measures
5 less than twice the first side (x), and the third
side measures 3 more than the second side. In
terms of x. what is the perimeter?

Answers

It will be 7.5cm because its base it’s bxh/2

$5,000 is invested at a rate of 7% compounded monthly. Determine the final balance after 5 years.

Answers

Answer:11,256

Step-by-step explanation:

you pay $2 to play a game in which you roll one fair die. If you roll a 5 on the first roll, you win $5. If you roll a 1 or 2, you win $3 . If not you lose your money. Find the expected value for this game.

Answers

Show the online response please but I say 4

Answer:

the answer is 4

Step-by-step explanation:

use the regression equation to predict the head circumference of a child who is 24.25 inches tall. y

Answers

The regression equation to predict the head circumference of a child who is 24.25 inches tall y=17.20 inches

The regression line with the least squares

y = 0.1827*x + 12.4932

Children that are 25.25 inches tall should have a mean head circumference that we can anticipate.

Let x = 25.75

y is thus equal to 0.1827*25.75 plus 12.4932.

b) The mean head circumference of kids who are 25.25 inches tall falls within the 95% confidence interval of

The Mean of the head circumference is 17.327, the standard deviation is 0.219, there are 11 participants, and there are 10 participants in step c.

y = 0.1827*x + 12.4932

The head circumference of a youngster who is 25.25 inches tall must be predicted.

Let x = 25.75

y is thus equal to 0.1827*25.75 plus 12.4932.

y=17.20 inches.

Know more about regression

https://brainly.com/question/28178214

#SPJ4

what is the most effluence first step to isolate the variable term on one side of this equation -9x=-4x+5

Answers

The first step to isolate the variable term on one side of the equation -9x = -4x + 5 is to add 4x to both sides of the equation. This gives us -9x + 4x = 5. Next, we can simplify the left hand side to -5x to isolate the variable term on one side of the equation. The isolated variable term is -5x.
Other Questions
what is virginia woolf quotes? Which root of insurgency discusses how foreign businesses can dominate critical portions? Does silicon need to be processed before it can be used according to the us department of education, who is most at risk to not complete high school in 2016 due to community factors such as ses and unsafe neighborhoods? The Americans made an alliance with France which led to the end of the Revolutionary War. What kind of factor is this? Economic Military Political Social Iwant Solution for the question Which approach and method is best between Keynes, Friedman and Lucas when considering an explanation on how the economy works? (As conclusion for an essay) If a flower has 26 chromosomes to create a new flower how many chromosomes would the sperm cell have In the bodyconclusionintroduction rebuttal of an essay the writer can summarize all the connections that were made between ideas and evidence through the essay. Look at the picture for each of the following extracts from advertisements identify and explain how ethos pathos or logos is being used construct a turing machine that will accept the following language on {a, b}: l = {w : |w| is odd} write 2 poems about something what was new and different for the art students' course of study at the bauhaus school of design? quizler What is a budget? Study question 3 on edg XYZ Industries sells two competing products, Xidgets and Yadgets. The demand equations for these goods are Qx=200-2P+Py Q=180+2P-2P, . where P, and P, are the prices that XYZ sets for Xidgets and Yadgets respectively, and Qx and Q, are the corresponding weekly demands for these goods. XYZ produces exactly as many units as it can sell per week, where the weekly production cost is . C=1600,+2300, +1000. (a) (5 pts) Find the prices that XYZ should set to maximize their weekly profit and the corresponding maximum weekly profit. (b) (2 pts) Justify your claim that the prices you found yield the absolute maximum weekly profit. Mr. Wilcox has been enrolled in Lexington Private Fee-for-Service (PFFS) Medicare Advantage Health Plan (Lexington) for several years What are the abbreviations for a femtosecond, a gigaliter, and a decimeter, respectively? Why do you think auditors must report significant deficienciesand material weaknesses to management and the audit committee? The goal of many successful organizations is a(n) ______ rate of growth in dividends. why is money a demotivator?