A circle has a diameter of 16 inches. What is the circumference of the circle using function on the calculator?

Candice buys a board thats is 12 feet long. the store incorrectly measures and prices the board at 13.2 feet. whats the percent

podryga [215]

Determine first the difference between the incorrectly measured board and the correct one. The subtraction would result to 1.2 ft. The percent error is calculated by dividing this value by the correct value and then multiply by 100%. (1.2 ft / 12 ft) x 100% = 100%. Thus, the percent error is 10%.

7 0

3 years ago

Read 2 more answers

In the figure, the ratio of the perimeter of rectangle ABDE to the perimeter of triangle BCD is 2/3 1 3/2 2 . The area of polygo

adelina 88 [10]

It would b 2/3 and the other one 2/4

6 0

3 years ago

A national survey conducted in 2011 among a simple random sample of 1,507 adults shows that 56% of Americans think the Civil War

Drupady [299]

Answer:

a) $z=4.658$

$p_v =P(z>4.65)=1-P(z$

b) Using the significance level assumed $\alpha=0.05$ we see that $p_v$ so we have enough evidence at this significance level to reject the null hypothesis. And on this case makes sense the claim that the proportion of Americans who thinks that the Civil War is still relevant to American politics and political life is higher than 50%.

c) The 90% confidence interval would be given (0.527;0.593).

We are confident that about 54% to 59% of all Americans think the Civil War is relevant.

Step-by-step explanation:

I )Part a

1) Data given and notation

n=1507 represent the random sample taken

X represent the Americans who thinks that the Civil War is still relevant to American politics and political life

$\hat p$ estimated proportion of Americans who thinks that the Civil War is still relevant to American politics and political life in the sample

$p_o=0.5$ is the value that we want to test since the problem says majority

$\alpha=0.05$ represent the significance level (no given, but is assumed)

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

p= population proportion of Americans who thinks that the Civil War is still relevant to American politics and political life

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that the proportion of Americans who thinks that the Civil War is still relevant to American politics and political life exceeds 50%(Majority). :

Null Hypothesis: $p \leq 0.5$

Alternative Hypothesis: $p >0.5$

We assume that the proportion follows a normal distribution.

This is a one tail upper test for the proportion of union membership.

The One-Sample Proportion Test is "used to assess whether a population proportion $\hat p$ is significantly (different,higher or less) from a hypothesized value $p_o$ ".

Check for the assumptions that he sample must satisfy in order to apply the test

a)The random sample needs to be representative: On this case the problem no mention about it but we can assume it.

b) The sample needs to be large enough

$np_o =1507*0.5=753.5>10$

$n(1-p_o)=1507*(1-0.5)=753.5>10$

3) Calculate the statistic

The statistic is calculated with the following formula:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o(1-p_o)}{n}}}$

On this case the value of $p_o=0.5$ is the value that we are testing and n = 1507.

$z=\frac{0.56 -0.5}{\sqrt{\frac{0.5(1-0.5)}{1507}}}=4.658$

The p value for the test would be:

$p_v =P(z>4.65)=1-P(z$

II) Part b

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

Based on the alternative hypothesis the p value would be given by:

$p_v =P(z>4.65)=1-P(z$

Using the significance level assumed $\alpha=0.05$ we see that $p_v$ so we have enough evidence at this significance level to reject the null hypothesis. And on this case makes sense the claim that the proportion of Americans who thinks that the Civil War is still relevant to American politics and political life is higher than 50%.

III) Part c

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 90% confidence interval the value of $\alpha=1-0.9=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.56 - 2.58 \sqrt{\frac{0.56(1-0.56)}{1507}}=0.527$

$0.56 + 2.58 \sqrt{\frac{0.56(1-0.56)}{1507}}=0.593$

And the 90% confidence interval would be given (0.527;0.593).

We are confident that about 54% to 59% of all Americans think the Civil War is relevant.

And this result agrees with the result of part b, since the interval not contains the value of 0.5 we can conclude that the proportion of Americans who thinks that the Civil War is still relevant to American politics and political life it's higher than 0.5 at 90% of confidence.

7 0

3 years ago

Out of 100 employees at a company, 92 employees either work part time or work 5 days each week. There are 14 employees who work

Alexus [3.1K]

Answer: 0.02

Step-by-step explanation:

OpenStudy (judygreeneyes):

Hi - If you are working on this kind of problem, you probably know the formula for the probability of a union of two events. Let's call working part time Event A, and let's call working 5 days a week Event B. Let's look at the information we are given. We are told that 14 people work part time, so that is P(A) = 14/100 - 0.14 . We are told that 80 employees work 5 days a week, so P(B) = 80/100 = .80 . We are given the union (there are 92 employees who work either one or the other), which is the union, P(A U B) = 92/100 = .92 .. The question is asking for the probability of someone working both part time and fll time, which is the intersection of events A and B, or P(A and B). If you recall the formula for the probability of the union, it is

P(A U B) = P(A) +P(B) - P(A and B).

The problem has given us each of these pieces except the intersection, so we can solve for it,

If you plug in P(A U B) = 0.92 and P(A) = 0.14, and P(B) = 0.80, you can solve for P(A and B), which will give you the answer.

I hope this helps you.

Credit: https://questioncove.com/updates/5734d282e4b06d54e1496ac8

7 0

3 years ago

Lester’s car can go 15.4 miles on 1 gallon of gas. How far can he go on 0.7 gallon?

MAVERICK [17]

Answer:

He can go 10.78 miles

Step-by-step explanation:

This problem can be solve by creating a proportion, knowing that 15.4 miles is to one gallon the same as "x" miles (our unknown) is to 0.7 gallons. This can be set in math terms as the equation that relates these two ratios of miles per gallon:

$\frac{15.4\,miles}{1\,gallon} =\frac{x }{0.7\,gallon}$

and to solve for the unknown number of mile, we multiply both sides of the equation by "0.7 gallon" in order to isolate our unknown:

$\frac{15.4\,miles}{1\,gallon} =\frac{x}{0.7\,gallon}\\\frac{15.4\,miles\,*\,0.7\,gallon}{1\,gallon} =x \\x=10.78\,miles$

7 0

4 years ago