City Hospital has a temporary shortage of nurses, so nurses have been working overtime.  A random sample of six nurses reported that the number of overtime hours they worked last week were: 7,   2,   4,   5,   4,   3 Compute the mean for the data set.

Use the table of data below and the formula for grouped data to estimate the sample mean. Class Limits f x x*f x^2*f 0.5 – 1.5 2 1 2 2 1.5 – 2.5 4 2 8 16 2.5 – 3.5 5 3 15 45 3.5 – 4.5 8 4 32 128 4.5 – 5.5 7 5 35 175 5.5 – 6.5 3 6 18 108 TOTALS 29 21 110 474

A frequency table has class limits of 5 – 9, 10 -14, 15 -19, 20 -24, and 25 – 29.  The class width of each class is 4.

Merchants are always concerned when temperatures are extremely cold because they claim that they have fewer shoppers the colder it gets.  At Paradise Mall the merchant association did a study.  The results are contained in the table below.  Let x represent the noonday temperature in F and y represent the number of customers visiting the mall (in hundreds) that day. x 0 10 20 30 40 y 2 3 10 15 17 Calculate the correlation coefficient, r.

Ten equally qualified people apply for a job.  Three will be selected to interview.  How many different combinations of three people can be interviewed?

City Hospital has a temporary shortage of nurses, so nurses have been working overtime.  A random sample of six nurses reported that the number of overtime hours they worked last week were: 7,   2,   4,   5,   4,   3 Compute the mode of the data set.

Arapahoe Community College holds evening classes on Colorado state history.  The director of studies, wishing to konw the age distribution of students in the class, obtained the following information.  Ages are rounded to the nearest year. 63,   41,   28,   22,   45,   30,   43,   46,   35,   56,   27,   18 29,   20,   31,   19,   22,   32,   55,   54,   31,   63,   51,   39 29,   19,   27,   53,   51,   33,   58,   29,   65,   53,   56,   19

Weights of Pacific yellowfin tuna follow a normal distribution with mean weight μ = 68 lb and standard deviation σ = 12 lb.  A Pacific yellowfin tuna is caught at random.  Find the probability that its weight is less than 48 lbs.

Willard has just been given a ten-question multiple choice test in one of his classes.  Each question has five answers only one of which is correct.  Since Willard has not attended class recently, he does not know any of the answers.  Assume that Willard guesses randomly on all ten questions.  Find the probability that he will answer, at most, 3 questions correctly. 

Dream Travel Tours contracted with Slick Rent-a-Car to provide rental cars to travelers.  Slick went out of business and did not provide the prepaid rental cars to 20 travelers.  The travelers demanded refunds from Dream Travel.  The times elapsed between refund requests and the actual refunds were as follows (in days): 26,   49,   22,   58,   43,   37,   48,   32,   21,   54, 42,   63,   27,   33,   47,   45,   67,   21,   48,   57 Make a stem and leaf display of the data.