the drying times for a certain type of cement are normally distributed with a standard deviation of 68 minutes. a researcher wishes to estimate the mean drying time for this type of cement. find the sample size needed to assure with 99% confidence that the sample mean will not differ from the population mean by more than a margin of error of 7 minutes

Answer:

B

Step-by-step explanation:

16 + 6 ← factor out 2 from each number

= 2(8 + 3)

Answer:

Below

Step-by-step explanation:

● x-20 = y+20 (1)

● 2(y-22) = x+22 (2)

This is a system of simulataneous equations

Let's simplify the expressions first

● x -20 = y + 20 (1)

Add 20 to both sides

● x -20 + 20 = y+20 +20

● x = y + 40 (1)

● 2(y-22) = x+22 (2)

● 2y - 44 = x +22

Substrat 22 from both sides

● 2y-44-22 = x+22-22

● 2y -66 = x (2)

This is the new system:

● x = y+40 (1)

● x = 2y-66 (2)

Substract (2) from (1)

● x-x = y+40-(2y-66)

● y+40-2y+66 = 0

● -y +106 = 0

● y = 106

Replace y with 106 in (1)

● x = y +40

● x = 106+40

● x = 146

So the solutions are (146,106)

The measure of the arc is option (c) 140°

In geometry, an arc is a curved line that is a part of a circle's circumference. The measure of an arc can be calculated using the angle of the arc, which is measured in degrees.

In the case of EBC, the measure of the arc is 140°. This is because we can use the Angle-Side-Angle (ASA) congruence theorem, which states that two triangles are congruent if and only if two angles and the included side are equal.

In the case of EBC, we know that angle A equals 40° and angle C equals 90° so the only variable left is the measure of the arc, which is equal to 140°.

Therefore, the measure of EBC is 140°. This can be verified by drawing the triangle and measuring the arc with a protractor.

Therefore, option (c) is the right one.

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Complete Question:

What is the measure of arc  EBC when the values of Angle a nd c are 90 and 40 degree respectively.

a) 40°

b) 90°

c) 140°

d) 220°

2400 - 40x = 600

As she has not studied 600 flashcards still, we subtract unit rate from total.

40x - 600 = 2400

Here 'x' represent per hour. As he rents studio space for 600, subtracting this from total he earns by charging his students gives us the profit.

(600 + 40)x = 2400

Here 'x' represent mass. As masses are same for both. They can be joined.

Answer:

16

Step-by-step explanation:

1st group = 30% or .3 as a decimal

.3 * 40 = 12

2nd group = ate 7

Third group = 1/8 or .125 as a decimal

.125 * 20 = 5

12 + 7 + 5 = 24

40 -24 = 16

The recurrence relation for an is an = an-1 + an-2.  the number of ways to climb n stairs is equal to the sum of the number of ways to climb (n-1) stairs and the number of ways to climb (n-2) stairs.

To find a recurrence relation for an, the number of ways to climb n stairs if a person can take one stair or two stairs at a time, we can break it down into smaller subproblems.

Consider the last step taken to reach the nth stair. If the person took one step, there are an-1 ways to reach the (n-1)th stair. If the person took two steps, there are an-2 ways to reach the (n-2)th stair.

Since the person can only take one or two steps at a time, these are the only two possibilities.

Therefore, the recurrence relation for an is an = an-1 + an-2.

This means that the number of ways to climb n stairs is equal to the sum of the number of ways to climb (n-1) stairs and the number of ways to climb (n-2) stairs.

Note: This recurrence relation is based on the assumption that there are no other constraints or conditions given in the problem statement.

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Answer:

No because their ratios are not the same

Step-by-step explanation:

The scalar from 5 to 10 is 2 but from 3 to 4, its 4/3.

Answer:

============================

The total deposit over 12 weeks:

Equation in general form:

Answer:

5x + 2y = 18  >  3x + 7y = 29​

Step-by-step explanation:

5x + 2y = 18 compare to 3x + 7y = 29​

5x + 2y = 18

-5x        -5x

2y = -5x + 18

/2       /2

y = -5/2x + 9    -5/2 = -2.5  

3x + 7y = 29​

-3x         -3x

7y = -3x + 29

/7       /7

y = -3/7x + 29/7     -3/7 = 0.43     29/7 = 4.14

y = -5/2x + 9  > y = -3/7x + 29/7

Hope this helps!

Answer:

x = 8

Step-by-step explanation:

5(x/2 + 3) = 35

5x/2 + 15 = 35

5x/2 = 35 - 15

5x/2 = 20

5x/2 • 2 = 20 • 2

5x = 40

5x/5 = 40/5

x = 8

Hope This Helps! •v•

Answer:

y = -x - 6

Step-by-step explanation:

Given:

From:

\(\displaystyle \large{y=mx+b}\)

where m = slope and b = y-intercept. Therefore:

\(\displaystyle \large{y=-1x+b}\\\displaystyle \large{y=-x+b}\)

Since the equation passes through a point (2,-8). Substitute x = 2 and y = -8 in and solve for b:

\(\displaystyle \large{-8=-2+b}\\\displaystyle \large{-8+2=b}\\\displaystyle \large{b=-6}\)

Then substitute b-value in the equation:

\(\displaystyle \large{y=-x+b}\\\displaystyle \large{\therefore y=-x-6}\)

Hence, the equation is y = -x - 6

Answer:

y = -x - 6

Step-by-step explanation:

Hi there!

We are given that a line contains the point (2, -8), and a slope of -1

We want to find the equation of this line, in slope-intercept form

Slope-intercept form is written using the formula y=mx+b, where m is the slope and b is the value of y at the y intercept, hence the name

Notice how we are already given the slope - we can immediately plug that into the equation as m.

y = -x + b (when -1 is the coefficient in front of a number, there is no need to write '-1x'. '-x' is sufficient.)

Now, we need to find b

The line contains the point (2, -8), meaning that it is a solution to the equation. If this is the case, that means that the values of x and y that make up the point will make the equation true, when you plug those values into the equation

So substitute 2 as x and -8 as y:

-8 = -2 + b

Add 2 to both sides

-8 = -2 + b

+2    + 2

_____________

-6 = b

Substitute -6 as b.

y = -x -6

Hope this helps!

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Answer:

They are the same line. It means that they are overlapping line.

Answer:

Overlapping

Step-by-step explanation:

Divide every term of the second equation, it would be 2x + y = 6, which is the same as the first equation.

Answer :

$456

Step-by-step explanation:

Donation by local business :\( \frac{15}{100} \times 380 \\ \\ \frac{15 \times 38}{10} = 57\)

= $57

Donation by the principal of the student's school :

\( \frac{5}{100} \times 380 \\ \\ = \frac{5 \times 38}{10} = 19\)

= $19

The total money received by the food pantry :

$380 + $57 + $19

= $456

0.15 (380) = 57

0.05 (380) = 19

Let p = Food Pantry money in total

p = 380 + 57 + 19

p = $456

A study conducted in 2004 examined the usage of cable television and radio among 10 individuals to determine if there was a significant difference in the average hours spent on each medium. Using a significance level of 0.05, statistical analysis was performed to test for a disparity between the population mean usage of cable television and radio.

The researchers collected data on the number of hours per week spent watching cable television and listening to the radio from a sample of 10 individuals. The objective was to determine if there was a significant difference in the average usage between cable television and radio, considering the increasing competition among various entertainment options.

To test for a difference between the population mean usage for cable television and radio, a statistical hypothesis test was conducted. The significance level (α) of 0.05 was chosen, which means that the results would be considered statistically significant if the probability of obtaining such extreme results by chance alone was less than 5%.

The test compared the means of the two samples, namely the average hours spent watching cable television and listening to the radio. By analyzing the data using appropriate statistical techniques, such as a two-sample t-test, the researchers determined whether the observed difference in means was statistically significant or could be attributed to random variation.

After conducting the hypothesis test, if the p-value associated with the test statistic was less than 0.05, it would indicate that there was a significant difference between the population mean usage of cable television and radio. Conversely, if the p-value was greater than 0.05, there would be insufficient evidence to conclude a significant disparity.

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Answer:

x=4

Step-by-step explanation:

First you need to factor the equation. You can do this by multiplying the numbers by eachother so they have a denominatior of 12.

You would come out to have this...

((x+2)*4)/12 + ((2x-4)*3)/4=3

At this point you can combine the numerators over the common denominator.

((x+2)*4+(2x-4)*3)/12=3

You can now rewrite the equation into factored form.

5x-2/6=3

Multiply both sides of the equation by 6.

5x-2=18

move the terms not containing x to the right

5x=20

and divide by 5

x=4

Answer:

AAS., B in D

Step-by-step explanation:

Answer:

hi,

Step-by-step explanation:

Let say P=(x,y) a point of the locus

\(Distance\ from\ P\ to\ (2,1)= \sqrt{(x-2)^2+(y-1)^2} \\Distance\ from\ P\ to\ (1,2)= \sqrt{(x-1)^2+(y-2)^2} \\\\\sqrt{(x-2)^2+(y-1)^2} =2*\sqrt{(x-1)^2+(y-2)^2} \\\\(x-2)^2+(y-1)^2=4*((x-1)^2+(y-2)^2)\\\\3x^2-4x+3y^2-14y+15=0\\\\\)

\(3x^2-4x+3y^2-14y+15=0\\3(x^2-2*\dfrac{2}{3} x)+3(y^2-2*\dfrac{7}{3}*y) +15=0\\3(x^2-2*\dfrac{2}{3}*x+\dfrac{4}{9})+3(y^2-2*\dfrac{7}{3}*y+\dfrac{49}{9} ) +15-\dfrac{4}{3}-\dfrac{49}{3}=0\\\\3(x-\dfrac{2}{3})^2+3(y-\dfrac{7}{3})^2-\dfrac{8}{3}=0\\\\\\\boxed{(x-\dfrac{2}{3})^2+(y-\dfrac{7}{3})^2=\dfrac{8}{9}}\\\\\)

Locus is the circle of center (2/3,7/3) and radius =2√2  /3.

The solutions are 3.49206 and −1.05e+11

The three floating-point numbers a, b, c as inputs that represent the coefficients of a quadratic equation: a∗x^2+b∗x+c=0.

To find the solutions using math functions to solve a quadratic equation for the given coefficients of the quadratic equation: a = 1.5e-05, b = 1.575e+06, and c = -5.5e+06.

Using the quadratic formula, we have;  

x = (-b ± sqrt(b^2 - 4ac))/2a

When a = 1.5e-05, b = 1.575e+06, and c = -5.5e+06;

x = (-1.575e+06 ± sqrt(1.575e+06^2 - 4(1.5e-05)(-5.5e+06)))/2(1.5e-05)

= (-1.575e+06 ± sqrt(2.480625e+12 + 330000))/3e-05

= (-1.575e+06 ± sqrt(2.48062825e+12))/3e-05

= (-1.575e+06 ± 1.573468e+06)/3e-05

= (-1.05e+11 or 3.49206)

Therefore, the solutions are 3.49206 and −1.05e+11.

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Engineers can be held most morally blameworthy for foreseeable harms resulting from technological innovations, engineers have a responsibility to anticipate the potential consequences of their work,

and to take steps to mitigate those consequences. If they fail to do so, and their work results in harm, they can be held morally blameworthy. When engineers develop new technologies, they have a responsibility to consider the potential consequences of their work.

They need to think about how their technology could be used, and whether it could be used to harm people or the environment.

They also need to consider how their technology could be misused, and what steps they can take to prevent misuse.

If engineers fail to consider the potential consequences of their work, and their work results in harm, they can be held morally blameworthy. This is because they have a duty to protect the public from harm, and they have failed to fulfill that duty.

For example, engineers who develop new weapons systems have a responsibility to consider the potential consequences of their work. They need to think about how their weapons could be used,

and whether they could be used to kill or injure innocent people. They also need to consider how their weapons could be misused, and what steps they can take to prevent misuse.

If engineers fail to consider the potential consequences of their work, and their weapons are used to kill or injure innocent people, they can be held morally blameworthy. This is because they have a duty to protect the public from harm, and they have failed to fulfill that duty.

It is important to note that engineers cannot be held morally blameworthy for unforeseeable harms. This is because they did not have the opportunity to anticipate the harm, and they could not have taken steps to prevent it.

For example, engineers who develop new medical treatments cannot be held morally blameworthy if the treatments have unforeseen side effects. This is because the engineers did not have the opportunity to anticipate the side effects, and they could not have taken steps to prevent them.

In conclusion, engineers can be held morally blameworthy for foreseeable harms resulting from technological innovations.

This is because they have a responsibility to anticipate the potential consequences of their work, and to take steps to mitigate those consequences.

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The correct answer is Option c.  The alternative hypothesis is often a statement about the population the researcher suspects is true, and is trying to find evidence for.

Hypothesis testing is a statistical method that helps researchers determine if there is a significant difference between two or more data sets. Hypothesis testing is a framework for making data-driven decisions. Before hypothesis testing, a hypothesis must be developed, which is a statement or assumption about the population parameter.

Hypotheses are either formulated as a null hypothesis or an alternative hypothesis. The null hypothesis usually assumes that there is no relationship between the variables, while the alternative hypothesis is formulated to either reject or accept the null hypothesis.

In formulating hypotheses for a statistical test of significance, the alternative hypothesis is often a statement about the population the researcher suspects is true and is trying to find evidence for.

This hypothesis must be testable through statistical analysis, and it must also be falsifiable. The alternative hypothesis is used in statistical analysis to determine the significance of the results obtained from the sample. In most cases, the level of significance is set at 0.05.

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we will use the formula of tan(A+B)= (tanA+tanB)/(1-tanAtanB)

and tan(A-B)= (tanA-tanB)/(1+tanAtanB)

tan[(pie/4)+(x/2)]= [1+tan(x/2)]/[1-tan(x/2)] ......(1)

tan[(pie/4)-(x/2)]= [1-tan(x/2)]/[1+tan(x/2)]......(2)

now add the equation (1) and (2) which is LHS of question. So we get:

{[1+tan(x/2)]^2 + [1- tan(x/2)]^2}/1-tan^2(x/2)=2[1+tan^2(x/2)]/1-tan^2(x/2)= 2/cosx = 2secx =RHS

Hence proved.

Answer:

uhmmm try to search on google ‍♂️

Answer:

a)10ft²

b)6yd

Step-by-step explanation:

a) area = length x width (square has same length for each side)

so,

\( \sqrt{100} = 10\)

b) perimeter means total of all side.

in this case square got 4 equal side.

so,

\(24 \div 4 = 6\)

Answer:

multiply both side by 2 to get rid of the 2

z(2)=6(2)

z=12

Answer: 13

Step-by-step explanation:

Answer:

Carly will have to spend $7.25

Step-by-step explanation:

We know that:

1 pound of turkey = $5.80

To find how much 1.25 pounds of turkey will cost, multiply:

5.80 x 1.25 = 7.25

Therefore, 1.25 pounds of turkey will cost $7.25

I really hope this helps!

-SpaceMarsh

We cannot determine the exact amount of fencing Sam needs.

To find out how many feet of fencing Sam needs, we need to calculate the total perimeter of his garden.

First, let's find the length of the two sides that are already near a fence. Since these sides are already taken care of, we don't need to include them in our calculation.

Now, let's focus on the other two sides that are 15 and 23 feet long. To find the total perimeter, we need to add the lengths of all four sides together.

So, the total perimeter is 15 + 23 + (length of the two sides near the fence) + (length of the other side near the fence).

Since we don't know the length of the sides near the fence, we cannot calculate the exact length of the total perimeter.

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Answer:

C: {−5, 1)

Step-by-step explanation:

Starting with −2|−2x−4|=−12, divide both sides by -2:

|−2x−4| =  6

Reduce this by dividing all terms by 2:

|-x - 2| = 3

This is equivalent to   x + 2 = 3  and  x + 2 = - 3

Solving thse two equations, we get x = 1 and x = -5

And so the solution set is  C: {−5, 1)

Answer:

abc i need to put a real answer

Step-by-step explanation: