Chapter 6, Section 1-CI, Exercise 011

Use the normal distribution to find a confidence interval for a proportionpgiven the relevant sample results. Give the best point estimate forp, the margin of error, and the confidence interval. Assume the results come from a random sample.

A 99% confidence interval forpgiven thatp^=0.4 andn=500.

Round your answer for the best point estimate to two decimal places, and your answers for the margin of error and the confidence interval to three decimal places.

Best point estimate =

Margin of error=

The 99% confidence interval is __________r; to __________.

.

Chapter 6, Section 4-HT, Exercise 210

Use thet-distribution and the given sample results to complete the test of the given hypotheses. Assume the results come from random samples, and if the sample sizes are small, assume the underlying distributions are relatively normal.

TestH0:1=2 vsHa:12using the sample resultsx1=15.3,s1=11.6 withn1=100 andx2=18.4,s2=14.3withn2=80.

(a) Give the test statistic and thep-value.

Round your answer for the test statistic to two decimal places and your answer for thep-value to three decimal places.

test statistic =__________

p-value =__________

(b) What is the conclusion of the test? Test at a10%level.

RejectH0.

Do not rejectH0.

Chapter 6, Section 1-CI, Exercise 011

Use the computer output to estimate the intercept0 and the slope1.

The regression equation isY=834-3.3X.

Predictor Coef SE Coef T P

Constant 834.197 90.67 9.20 0.000

X -3.295 1.080 -3.05 0.006

Intercept0: __________

Slope1: __________