Problem solving steps and formulas required

1. A sample of twelve students were given an arithmetic test, and the times (in minutes) to complete it were as follows: 10, 9, 12, 11, 8, 16, 9, 7, 8, 6, 12, 12 a) Calculate the mean, median and mode. b) Calculate the range, standard deviation and variance. c) Calculate the coefficient of skewness and interpret.

2. The average age of the accountants at Three Rivers Corporation is 26 years, with a standard deviation of 6 years. The average salary of the accountants is $31,000, with a standard deviation of $4,000. Compare the variations of age and income?

3. The following data represent the daily earnings ($) of the employees in an assembly plant. Construct a frequency distribution. Be sure to include a relative frequency column. 120 60 132 96 116 92 116 116 100 100 160 166 196 176 108 126 92 192 144 128 152 128 144 130 68 116 140 96 168 126 98 144 116 72 180 66 176 88 164 120

4. The Tourist Bureau of Quebec surveyed a sample of tourists as they left to return to the US. One of the questions was: How many days did you spend in Quebec? The responses were recorded into the following table: Days Frequency 3 to 6 8 6 to 9 16 9 to 12 25 12 to 15 13 15 to 18 5 Calculate: a) mean b) median c) mode d) range e) standard deviation f) variance g) first quartile h) 90th percentile i) Assuming the distribution is bell-shaped, approximately 95% of tourists stayed between how many days? j) Determine the coefficient of skewness and interpret.

5. The mean amount spent by customers at Zehr's is normally distributed with a mean of $75 and a standard deviation of $5. What percent of the customers spend between $65 and $85?

6. The normal daily high temperatures (in degrees Fahrenheit) in January for 10 selected cities are as follows: 50, 37, 29, 54, 30, 61, 47, 38, 34, 61 The normal monthly precipitation (in inches) for these same cities is listed below: 4.8, 2.6, 1.5, 1.8, 1.8, 3.3, 5.1, 1.1, 1.8, 2.5 Compare the relative dispersion between the two data sets.

7. The amount of time (minutes) to get to work for 14 employees is as follows: 22, 17, 30, 9, 12, 45, 15, 28, 19, 20, 32, 5, 25, and 20. Calculate the population mean, median, mode, range, standard deviation and variance.

8. SCCoast, an Internet provider, developed the following frequency distribution on the age of Internet users. Find the mean, median and 85th percentile. AGE (Years) Frequency 10 to 20 3 20 to 30 7 30 to 40 18 40 to 50 20 50 to 60 12