Cal saved half of his paycheck and $50 he got from his grandpa for his birthday. He has

Three women, Chantel, Marissa, and Qian, enjoy running laps around a circular track. Each women runs at a constant speed. It tak

lubasha [3.4K]

It takes 150 seconds for Qian to complete the track.

Let she runs the track in the clockwise direction.

In 60 seconds, she runs $\frac{60}{150}$ = $\frac{2}{5}$ th of the track.

Since she meets Marissa, who is running in the opposite (counter clockwise) direction in every 60 seconds, Marissa should have completed $\frac{3}{5}$ th of the track.

Chantel meets Marissa in every 300 seconds.

So, in 60 seconds, she advances Marissa by $\frac{1}{5}$ th of the track.

Hence, in 300 seconds, Qian, Marissa and Chantel all meets at the starting point.

ALITER;

Marissa meets Qian in every 60 seconds.

So, Marissa and Qian meet each other in 60th, 120th, 180th, 240th and 300th second.

But, it is given that Chantel meets Marissa in every 300 seconds.

So, in 300 seconds, Qian, Marissa and Chantel meet each other.

6 0

3 years ago

In the book Essentials of Marketing Research, William R. Dillon, Thomas J. Madden, and Neil H. Firtle discuss a research proposa

MakcuM [25]

Answer:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

$z=\frac{0.179-0.15}{\sqrt{0.17(1-0.17)(\frac{1}{140}+\frac{1}{60})}}=0.500$

$p_v =2*P(Z>0.500)=0.617$

So the p value is a very low value and using any significance level for example $\alpha=0.05, 0,1,0.15$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the two proportions NOT differs significantly.

Step-by-step explanation:

Data given and notation

$X_{1}=25$ represent the number of homeowners who would buy the security system

$X_{2}=9$ represent the number of renters who would buy the security system

$n_{1}=140$ sample 1

$n_{2}=60$ sample 2

$p_{1}=\frac{25}{140}=0.179$ represent the proportion of homeowners who would buy the security system

$p_{2}=\frac{9}{60}= 0.15$ represent the proportion of renters who would buy the security system

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the two proportions differs , the system of hypothesis would be:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{25+9}{140+60}=0.17$

Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.179-0.15}{\sqrt{0.17(1-0.17)(\frac{1}{140}+\frac{1}{60})}}=0.500$

Statistical decision

For this case we don't have a significance level provided $\alpha$ , but we can calculate the p value for this test.

Since is a two sided test the p value would be:

$p_v =2*P(Z>0.500)=0.617$

So the p value is a very low value and using any significance level for example $\alpha=0.05, 0,1,0.15$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the two proportions NOT differs significantly.

6 0

3 years ago

Vanessa has scored 45 32 and 37 are three math quizzes she will take one more quiz and she wants a quiz average of at least 40 w

dedylja [7]

She must at least score a 38
To get the average you need to add 45 + 32 + 37 together than divide it by the amount of numbers added, in this case 3.

45 + 32 + 37 = 114
114÷3 = 38

3 0

3 years ago

Read 2 more answers

How can you solve problems involving direct variation?

never [62]

Answer:

Solving a Direct Variation Problem

Write the variation equation: y = kx or k = y/x.

Substitute in for the given values and find the value of k.

Rewrite the variation equation: y = kx with the known value of k.

Substitute the remaining values and find the unknown.

Step-by-step explanation:

8 0

3 years ago

Val needs to find the area enclosed by the figure. The figure is made by attaching semicircles to each side of a 58-by-58 squar

Savatey [412]

Answer:

We need to find the area of the semicircles + the area of the square.

The area of a square is equal to the square of the lenght of one side.

As = L^2 = 58m^2 = 3,364 m^2

Now, each of the semicircles has a diameter of 58m, and we have that the area of a circle is equal to:

Ac = pi*(d/2)^2 = 3.14*(58m/2)^2 = 3.14(27m)^2 = 2,289.06m^2

And the area of a semicircle is half of that, so the area of each semicircle is:

a = (2,289.06m^2)/2 = 1,144.53m^2

And we have 4 of those, so the total area of the semicircles is:

4*a = 4* 1,144.53m^2 = 4578.12m^2

Now, we need to add the area of the square 3,364 m^2 + 4578.12m^2 = 7942.12m^2

This is nothing like the provided anwer of Val, so the numbers of val may be wrong.

4 0

3 years ago