1.A surveyasked, "How many tattoos do you currently have on yourbody?" Of the 1203 malessurveyed, 178 responded that they had at least one tattoo. Of the 1055 femalessurveyed, 140 responded that they had at least one tattoo. Construct a 95% confidence interval to judge whether the proportion of males that have at least one tattoo differs significantly from the proportion of females that have at least one tattoo. Interpret the interval.

Let p1 represent the proportion of males with tattoos and p2 represent the proportion of females with tattoos. Find the 95% confidence interval for p1p2.

The lower bound is _____

.

The upper bound is ______

.

(Round to three decimal places asneeded.)

Interpret the interval.

A.

There is 95% confidence that the difference of the proportions is in the interval. Conclude that there is insufficientevidenceofa significant difference in the proportion of males and females that have at least one tattoo.

B.

There is a 95% probability that the difference of the proportions is in the interval. Conclude that there is a significant difference in the proportion of males and females that have at least one tattoo.

C.

There is a 95% probability that the difference of the proportions is in the interval. Conclude that there is insufficientevidenceofa significant difference in the proportion of males and females that have at least one tattoo.

D.

There is 95% confidence that the difference of the proportions is in the interval. Conclude that there is a significant difference in the proportion of males and females that have at least one tattoo.

2.Find the population mean or sample mean as indicated.

Population: 3, 1, 15, 16, 25

Select the correct choice below and fill in the answer box to right choice.

A.

=

B.

x=

3.Construct a confidence interval for p1p2 at the given level of confidence.

x1=398, n1=541, x2=419, n2=597, 99% confidence

The researchers are ____% confident the difference between the two populationproportions, p1p2, is between____and _____

(Use ascending order. integer or decimal rounded to three decimal places asneeded.)

4.An insurance company crashed four cars in succession at 5 miles per hour. The cost of repair for each of the four crashes was $426, $452, $404, $212. Compute therange, samplevariance, and sample standard deviation cost of repair.

The range is $___

s2=____ dollars2

(Round to the nearest whole number asneeded.)

s=$____

(Round to two decimal places asneeded.)