Question

sorry for spamming multiples

The amount of time adults spend watching television is closely monitored by firms because this helps to determine advertising pricing for commercials. Complete parts​ (a) through​ (b).

​(a) According to a certain​ survey, adults spend 2.25 hours per day watching television on a weekday. Assume that the standard deviation for​ "time spent watching television on a​ weekday" is 1.93 hours. If a random sample of 60 adults is​ obtained, describe the sampling distribution of x overbar​, the mean amount of time spent watching television on a weekday.

Does x overbar have a

a uniform distribution

is approximately normal

with mu Subscript x overbarequals

nothing and sigma Subscript x overbarequals

nothing.

​(Round to six decimal places as​ needed.)

​(b) Determine the probability that a random sample of 60 adults results in a mean time watching television on a weekday of between 2 and 3 hours.

The probability is

nothing. ​(Round to four decimal places as​ needed.)

and

The following data represent the pH of rain for a random sample of 12 rain dates in a particular region. A normal probability plot suggests the data could come from a population that is normally distributed. A boxplot indicates there are no outliers. The sample standard deviation is s equals 0.318. Construct and interpret a 99​% confidence interval for the standard deviation pH of rainwater in this region.

4.69

5.12

4.92

4.77

4.73

4.73

5.76

4.84

4.97

4.72

4.83

4.50

Select the correct choice below and fill in the answer boxes to complete your choice.

​(Use ascending order. Round to three decimal places as​ needed.)

A.

There is a 99​% probability that the true population standard deviation is between

_ and _

B.

If repeated samples are​ taken, 99​% of them will have the sample standard deviation between

_ and

_

C.

There is 99​% confidence that the population standard deviation is between _ and _

and

A survey of 2287 adults in a certain large country aged 18 and older conducted by a reputable polling organization found that 429 have donated blood in the past two years. Complete parts

​(a) through​ (b).

​(a) Obtain a point estimate for the population proportion of adults in the country aged 18 and older who have donated blood in the past two years.

p^ equals _

​(Round to three decimal places as​ needed.)

​(b) Construct and interpret a 90​% confidence interval for the population proportion of adults in the country who have donated blood in the past two years. Select the correct choice below and fill in any answer boxes within your choice.

A. We are _​% confident the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between _ and _

B. There is a _​% probability the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between _ and _

and

According to a study conducted by a statistical​ organization, the proportion of people who are satisfied with the way things are going in their lives is 0.82. Suppose that a random sample of 100 people is obtained. Complete parts​ (a) through​ (b) below.

​(a) Describe the sampling distribution of ModifyingAbove p with caret​, the proportion of people who are satisfied with the way things are going in their life. Be sure to verify the model requirements.

Since the sample size is

▼

than​ 5% of the population size and ​np(1minus​p)equals

nothinggreater than or equals​10, the distribution of ModifyingAbove p with caret is

▼

with mu Subscript ModifyingAbove p with caret Baseline equals

nothing and sigma Subscript ModifyingAbove p with caret Baseline equals

nothing.

​(Round to three decimal places as​ needed.)

​(b) In the sample obtained in part​ (a), what is the probability that the proportion who are satisfied with the way things are going in their life exceeds 0.86​?

The probability that the proportion who are satisfied with the way things are going in their life exceeds 0.86 is

Answer 1