The director of employee benefits at a midsize company wants to determine the amount spent on health care by the typical hourly worker in the company.  A random sample of 21 workers is selected and the amount they spent on their families’ health care needs during the past year was collected and used to create the graphics below.  The director wishes to determine if the average hourly employee in the company spent less than $400 per year on his or her family’s health care needs.  Would conducting a hypothesis test using the t-distribution be appropriate in this situation?

Which of these statements does not contain a statistical mistake about correlation coefficient, r?

A dot plot of the speeds of a sample of 50 cars passing a policeman with a radar gun is shown below.   What proportion of motorists were driving above the posted speed limit of 65 miles per hour?

Suppose we have the following five number summary: Min = 6        Q1 = 11     Median = 12        Q3 = 14    Max = 19 Then, according to the fence rule formula: :

Use the following situation to answer the next three questions. A random sample of records of home sales from March 1 to July 1, 2010 from the files maintained by the Charlottesville Board of Realtors gives the Price (in dollars) and Size (in square feet) of 32 homes.  The regression model is as follows: Predicted Price = 47,820 + What price would you predict for a 2,500 square-foot house in this market?

What is the proper way to interpret a 95% confidence level (or the confidence interval procedure)?

Suppose two sections of the same class take the same exam and produce the results shown in the following histograms.  Which section had a higher standard deviation on the exam and why?

Male players at the high school, college, and professional ranks use regulation basketballs that weigh on average 22 ounces with a standard deviation of 1 ounce.  Assume that the weights of the basketballs are Normally distributed.  If a regulation basketball is randomly selected, what is the probability that it will weigh exactly 22.5 ounces?  Choose the best answer.

The objective of statistical inference is to:

Which of the following scenarios should not use a paired t-test?