Skew, coefficients of variation, class limits etc.

1. A group of 100 students were surveyed about their interest in a new International Studies program. Interest was measured in terms of high, medium, or low. 30 students responded high interest; 50 students responded medium interest; 40 students responded low interest. What is the relative frequency of students with high interest?

2. Refer to the following information from a frequency distribution for heights of college women recorded to the nearest inch: The first two class midpoints are 62.5" and 65.5". What are the class limits for the third class?

3. Five students were given a page of problems with the instructions to solve as many as they could in one hour. Five students solved the following number of problems: 12, 10, 8, 6 and 4. What is the arithmetic mean number of minutes required per problem? 7.5

4. David Electronics had a profit of $10 million in 2002. Profit doubled from 2002 to 2003 and profit increased eight fold from 2003 to 2004. What was the annual geometric mean rate of growth from 2002 to 2004?

5. The research director of a large oil company conducted a study of the buying habits of consumers with respect to the amount of gasoline purchased at full-service pumps. The arithmetic mean amount is 11.5 gallons and the median amount is 11.95 gallons. The standard deviation of the sample is 4.5 gallons. What is the Pearson's coefficient of skewness?

6. The annual incomes of the five vice presidents of Elly's Industries are: $41,000, $38,000, $32,000, $33,000 and $50,000. The annual incomes of Unique, another firm similar to Elly's Industries, were also studied and found to have a mean of $38,900 and a standard deviation of $6,612. What company has the greater coefficient of variation?