1.A random sample of 40 adults with no children under the age of 18 years results in a mean daily leisure time of 5.28 hours, with a standard deviation of 2.28 hours. A random sample of 40 adults with children under the age of 18 results in a mean daily leisure time of 4.48 hours, with a standard deviation of 1.88 hours. Construct and interpret a 95% confidence interval for the mean difference in leisure time between adults with no children and adults with children 12.

Let 1 represent the mean leisure hours of adults with no children under the age of 18 and 2 represent the mean leisure hours of adults with children under the age of 18.

The 95% confidence interval for 12 is the range from___hours____hours.

(Round to two decimal places asneeded.)

What is the interpretation of this confidenceinterval?

A.

There is 95% confidence that the difference of the means is in the interval. Conclude that there is a significant difference in the number of leisure hours.

B.

There is 95% confidence that the difference of the means is in the interval. Conclude that there is insufficientevidenceofa significant difference in the number of leisure hours.

C.

There is a 95% probability that the difference of the means is in the interval. Conclude that there is insufficient evidence of a significant difference in the number of leisure hours.

D.

There is a 95% probability that the difference of the means is in the interval. Conclude that there is a significant difference in the number of leisure hours

2.A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained physical activity. What sample size should be obtained if she wishes the estimate to be within five percentage points with 95% confidence, assuming that

(a) she uses the estimates of 21.4% male and 19.6% female from a previousyear?

(b) she does not use any priorestimates?

(a) n=

(Round up to the nearest wholenumber.)

(b) n=

(Round up to the nearest wholenumber.)

3.Determine x and x from the given parameters of the population and sample size.

=83, =21, n=49

x=

x=