You want to compute a 93% confidence interval for a population mean.  Assume that the population standard deviation is known to be 10 and the sample size is 50.  The value of z* to be used in this calculation is

What can be said when our P-value is 0.0324 at the 1% significance level?

Jefferson Valley Bank advertises that their customers wait on average only 6 minutes to get serviced. The listed values below are waiting times (in minutes) of customers at the Jefferson Valley Bank, where customers enter a single waiting line that feeds three teller windows. Is there evidence that the customers average wait time differs from the 6 minutes as advertised? Assume

Sam randomly selected 25 pistons from the production line and measured their radii. The standard deviation of these measurements was .33 inches. Does this give good evidence that the population radii have a standard deviation of less than .38? Assume

A statistic is said to be biased if

A 95% confidence interval for the mean number of bacteria in a Petri dish is calculated as (17.6, 47.6).  The margin of error for this study was

The drug Ziac is used to treat hypertension. In a clinical test, 33 of 120 Ziac users experienced the adverse symptom of dizziness. Construct a 90% confidence interval estimate for the percentage of all Ziac users who experience dizziness. Show all work for full credit.

What can be said when our P-value is 0.0712 at the 10% significance level?

In order for the margin of error to decrease in a confidence interval, one of what two things must happen?

For a study of the development of the thymus gland, researchers weighed the glands of six chick embryos after 14 days of incubation. The thymus weights (mg) were as follows:  33.8     27.3     30.8     32.6     43.5     47.6   a. Find a 98% confidence interval estimate for the population mean weight of the thymus glands of chick embryos. Show your work for full credit (6 points) b. Interpret the confidence interval in context of the problem. (2 points) c. If we kept the same level of confidence (98%) but take 4 times as large of a sample size, in general what would happen to the width of the confidence interval? You do NOT need to find the new interval (1 point). d. Find a 95% confidence interval estimate for the population variance of the thymus glands of chick embryos. Show your work for full credit (6 points)