sorry for spamming multiples
The amount of time adults spend watching television is closelymonitored by firms because this helps to determine advertisingpricing for commercials. Complete parts​ (a) through​ (b).
​(a) According to a certain​ survey, adults spend 2.25 hoursper day watching television on a weekday. Assume that the standarddeviation for​ \"time spent watching television on a​ weekday\" is1.93 hours. If a random sample of 60 adults is​ obtained, describethe sampling distribution of x overbar​, the mean amount of timespent 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 60adults results in a mean time watching television on a weekday ofbetween 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 randomsample of 12 rain dates in a particular region. A normalprobability plot suggests the data could come from a populationthat is normally distributed. A boxplot indicates there are nooutliers. The sample standard deviation is s equals 0.318.Construct and interpret a 99​% confidence interval for the standarddeviation 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 boxesto complete your choice.
​(Use ascending order. Round to three decimal places as​needed.)
A.
There is a 99​% probability that the true population standarddeviation is between
_ and _
B.
If repeated samples are​ taken, 99​% of them will have thesample standard deviation between
_ and
_
C.
There is 99​% confidence that the population standarddeviation is between _ and _
and
A survey of 2287 adults in a certain large country aged 18 andolder conducted by a reputable polling organization found that 429have donated blood in the past two years. Complete parts
​(a) through​ (b).
​(a) Obtain a point estimate for the population proportion ofadults in the country aged 18 and older who have donated blood inthe past two years.
p^ equals _
​(Round to three decimal places as​ needed.)
​(b) Construct and interpret a 90​% confidence interval forthe population proportion of adults in the country who have donatedblood in the past two years. Select the correct choice below andfill in any answer boxes within your choice.
A. We are _​% confident the proportion of adults in thecountry aged 18 and older who have donated blood in the past twoyears is between _ and _
B. There is a _​% probability the proportion of adults in thecountry aged 18 and older who have donated blood in the past twoyears is between _ and _
and
According to a study conducted by a statistical​ organization,the proportion of people who are satisfied with the way things aregoing in their lives is 0.82. Suppose that a random sample of 100people is obtained. Complete parts​ (a) through​ (b) below.
​(a) Describe the sampling distribution of ModifyingAbove pwith caret​, the proportion of people who are satisfied with theway things are going in their life. Be sure to verify the modelrequirements.
Since the sample size is
â–¼
than​ 5% of the population size and ​np(1minus​p)equals
nothinggreater than or equals​10, the distribution ofModifyingAbove p with caret is
â–¼
with mu Subscript ModifyingAbove p with caret Baselineequals
nothing and sigma Subscript ModifyingAbove p with caretBaseline equals
nothing.
​(Round to three decimal places as​ needed.)
​(b) In the sample obtained in part​ (a), what is theprobability that the proportion who are satisfied with the waythings are going in their life exceeds 0.86​?
The probability that the proportion who are satisfied with theway things are going in their life exceeds 0.86 is
