2. In ?2008, the per capital consumption of soft drinks in Country A was reported to be 18.69 gallons. Assume that the per capital consumption of soft drinks in Country A is approximately normally?distributed, with a mean of 18.69 gallons and a standard deviation of 5 gallons. Complete parts? (a) through? (d) below.

a.What is the probability that someone in Country A consumed more than 11 gallons of soft drinks in? 2008?

The probability is .

?(Round to four decimal places as? needed.)

b.What is the probability that someone in Country A consumed between 2

and 6 gallons of soft drinks in? 2008?

The probability is

.

?(Round to four decimal places as? needed.)

c. What is the probability that someone in Country A consumed less than 6

gallons of soft drinks in? 2008?

The probability is

.

?(Round to four decimal places as? needed.)

d. 98?% of the people in Country A consumed less than how many gallons of soft? drinks?

The probability is 98?% that someone in Country A consumed less than

gallons of soft drinks.

?(Round to two decimal places as? needed.)

3. According to a social media? blog, time spent on a certain social networking website has a mean of 17 minutes per visit. Assume that time spent on the social networking site per visit is normally distributed and that the standard deviation is 4 minutes. Complete parts? (a) through? (d) below.

a.If you select a random sample of 25

?sessions, what is the probability that the sample mean is between 16.5 and 17.5 minutes?

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

b.If you select a random sample of 25 sessions, what is the probability that the sample mean is between 16 and 17 minutes?

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

c.If you select a random sample of 144 sessions, what is the probability that the sample mean is between 16.5 and 17.5 minutes?

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

d.Explain the difference in the results of? (a) and? (c).

The sample size in? (c) is greater than the sample size in? (a), so the standard error of the mean? (or the standard deviation of the sampling? distribution) in? (c) is

?

greater

less

than in? (a). As the standard error

?

decreases,

increases,

values become more concentrated around the mean.? Therefore, the probability that the sample mean will fall in a region that includes the population mean will always

?

decrease

increase

when the sample size increases.

Enter your answer in each of the answer boxes.

4. n a random sample of 76 people, 38 are classified as? "successful."

a.Determine the sample ?proportion, p, of? "successful" people.

b.If the population proportion is 0.70?, determine the standard error of the proportion.

a.p=

?(Type an integer or a? decimal.)

b.p?=

?(Round to four decimal places as? needed.)

5. A study reports that 36?% of companies in Country A have three or more female board directors. Suppose you select a random sample of 100 respondents. Complete parts? (a) through? (c) below.

a.What is the probability that the sample will have between 33?%

and 43?% of companies in Country A that have three or more female board? directors?

The probability is

.

?(Round to four decimal places as? needed.)

b.The probability is 70?% that the sample percentage of Country A companies having three or more female board directors will be contained within what symmetrical limits of the population?percentage?

The probability is 70?% that the sample percentage will be contained above

?%

and below

?%.

?(Round to one decimal place as? needed.)

c.The probability is 99.7?% that the sample percentage of Country A companies having three or more female board directors will be contained within what symmetrical limits of the population?percentage?

The probability is 99.7?%

that the sample percentage will be contained above

?%

and below

?%.

?(Round to one decimal place as? needed.)