1. One of the major measures of the quality of service provided by any organization is the speed with which it responds to customer complaints. A large department store selling furniture and flooring, including wood tiling, had undergone a major expansion in the past several years. In particular, the flooring department had expanded from 2 installation crews to an installation supervisor, a measurer, and 15 installation crews. A sample of 50 complaints concerning wood tiling was selected during a recent year. The following data represent the number of days between the receipt of the complaint and the resolution of the complaint. 54 5 35 137 31 27 152 2 123 81 74 11 19 126 110 110 29 61 35 94 31 26 12 4 165 32 29 28 29 26 25 1 14 13 10 5 27 4 52 30 22 36 26 20 33 68 27 5 13 23 1.1 Compute the mean and median. 1.2 Compute the first quartile and third quartile. 1.3 Compute the range, interquartile range, variance and standard deviation. 1.4 Are the data skewed? If so, how? 1.5 On the basis of the result of 1.1 - 1.4, if you have to tell the president of the company how long a customer should expect to wait to have a complaint resolved, what would you say. Why? 2. A bank branch located in a commercial district of a city has developed an improved process for serving customers during the 12:00 noon to 1:00 pm peak lunch period. The time in minutes (operationally defined as the time a client enters the line to when he or she is served) of all customers during this hour is recorded over a period of one week. A random sample of 15 customers is selected and the results are as follows: 4.21 5.55 3.02 5.13 4.77 2.34 3.54 3.20 4.50 6.10 0.38 5.12 6.46 6.19 3.79 2.1 Compute the mean, median, first quartile, and third quartile. 2.2 Compute the variance, standard deviation, range, and interquartile range. 2.3 Are the data skewed? If so, how? 2.4 As a client walks into the branch office during the lunch hour, she asks the branch manager how long she can expect to wait. The branch manager replies, "Almost certainly less than five minutes." On the basis of the results of 1.1 and 1.2, evaluate the accuracy of this statement. 2.5 Suppose that the branch manager would like to guarantee a certain level of service during the peak lunch period. Failure to obtain service within a specified time would result in a small monetary payment or gift to a client. What waiting time do you think should be used as a cut off above which this gift would be provided? Explain your answer.

3. Twenty randomly chosen people are shown a television commercial and asked to rank it as to overall appeal on a scale of 1 to 100. The results are given below: 89, 75, 59, 96, 88, 71, 43, 62, 80, 92, 76, 72, 67, 60, 79, 85, 77, 83, 87, 53 3.1 Find the mean, median, mode and determine the skewness of the distribution. 3.2 Find the variance and standard deviation of the sample ratings. 3.3 What is the range between the first and third quartiles? 4. The Metro Manila Development Authority gathered the following data at a check station Avenue which has a speed limit of 60kph. 68 72 62 75 81 64 81 66 65 68 70 70 69 73 72 75 71 70 80 74 62 59 81 69 66 88 66 65 65 77 70 65 68 77 68 70 72 66 73 68 Compute all measures of central tendency and measures of variability of these data. Determine the skewness. How well did the motorists follow the speed limit along the avenue?