a. Write out the 95% confidence interval for the average monthly credit card Balance using the

correct confidence interval notation.

b. Interpret the confidence interval in context.

c. Show that the necessary condition/s hold for this confidence interval to be valid.

d. What is the margin of error of the 95% confidence interval estimate of the average credit card

balance?

e. Would the margin of error of a 99% confidence interval for the average credit card balance be

bigger or smaller than the margin of error of the 95% confidence interval? Briefly explain how

you reached this conclusion.

f. Calculate the sample size required to estimate the average credit card balance with a margin

of error of $50 with 95% confidence?

Data:

Descriptive: of a m condence Interval for the average monthly credit card balance Statistic Std. Error 01.02330 037.237 51350.09 81,007.00 51.030.00 1170591304 01.005.030 80.200 50.050 .004 .1 00 Descriptives of a 99% confidence interval for the average monthly credit card balance Statistic Std. Error Balance Mean $1,823.98 $37.237 99% Confidence Interval Lower Bound $1,727.84 for Mean Upper Bound $1,920.11 5% Trimmed Mean $1,754.21 Median $1,630.00 Variance 1178591.604 Std. Deviation $1,085.630 Minimum $150 Maximum $6,200 Range $6,050 Interquartile Range $1,350 Skewness .934 084 Kurtosis 400 .168