1. In a random sample of six microwave ovens, the mean repair cost was $65.00 and the standard deviation was $11.50. Assume the variable is normally distributed and use a t-distribution to constrcut a 95% confidence interval for the population mean ?. What is the margin of error for ??
The 95% confidence interval for the population mean ? is?
The margin of error is?
2. Construct the indicated confidence interval for the population mean ? using a t-distribution.
c=0.99, x(sample mean)=111, s=10, n=8
The confidence interval is?
3. Translate the excerpt below into a confidence interval for p and approximate the value of the level of confidence, c. In a survey of 8448 adults, 29.9% said they were taking vitamin E as a supplement. The survey's margin of error is plus or minus 1%
The confidence interval for the proportion p is?
4. In a survey of 7000 women, 4431 say they change their nail polish once a week. Construct a 99% confidence interval for the population proportion of women who change their nail polish once a week.
A 99% confidence interval for the population proportion is?