Y=|x-5|+|x+5|. if x>5

Heidi buys shirts for $20 and resells for $24. What is the percentage of Heidi's markup? Plz help me!!

Vadim26 [7]

20% because 4 dollars is 1/5 of 20

8 0

3 years ago

PLZ HLP! A dog is leashed to the corner of a house. How much running area does the dog have? Round your answer to the nearest sq

nadezda [96]

The area of a circle is area = pi x r^2

The full area = 3.14 x 20^2 = 1256 square feet.

The corner forms a 90 degree angle so the dirt area is 3/4 of a full circle.

Answer = 1256 x 3/4 = 942 square feet

7 0

2 years ago

Read 2 more answers

Suppose that the sample standard deviation was s = 5.1. Compute a 98% confidence interval for μ, the mean time spent volunteerin

NISA [10]

Answer:

The 95% confidence interval would be given by (5.139;5.861)

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

2) Confidence interval

Assuming that $\bar X =5.5$ and the ranfom sample n=1086.

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=1086-1=1085$

Since the Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.01,1085)".And we see that $t_{\alpha/2}=2.33$

Now we have everything in order to replace into formula (1):

$5.5-2.33\frac{5.1}{\sqrt{1086}}=5.139$

$5.5+2.333\frac{5.1}{\sqrt{1086}}=5.861$

So on this case the 95% confidence interval would be given by (5.139;5.861) We are 98% confident that the mean time spent volunteering for the population of parents of school-aged children is between these two values.

5 0

3 years ago

Which system of equations has the same solution as the system below??! PLEASE HELP

Fantom [35]

The answer is the second one, <em>2.</em>

3 0

3 years ago

In March 2015, a Nielsen global online survey "found that consumers are increasingly willing to pay more for socially responsibl

Veseljchak [2.6K]

Answer:

For this case the parameter of interest is given by:

$p$ who represent the true proportion of respondents said that they were willing to pay more for products and services from companies who are committed to positive social and environmental impact

For this case we have an estimation given for this parameter. The estimation comes from a sample of 30000 people selected in 60 countries and they got:

$\hat p = 0.66$

This value represent the best estimator for the true proportion since is an unbiased estimator of the real parameter:

$E(\hat p) = p$

Step-by-step explanation:

For this case the parameter of interest is given by:

$p$ who represent the true proportion of respondents said that they were willing to pay more for products and services from companies who are committed to positive social and environmental impact

For this case we have an estimation given for this parameter. The estimation comes from a sample of 30000 people selected in 60 countries and they got:

$\hat p = 0.66$

This value represent the best estimator for the true proportion since is an unbiased estimator of the real parameter:

$E(\hat p) = p$

For this case if we want to test if the population proportion is equal to an specified value we can use the one sample z test for a proportion:

Null hypothesis: $p=p_0$

Alternative hypothesis: $p \neq p_o$

When we conduct a proportion test we need to use the z statisitc, and the is given by:

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

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

6 0

3 years ago