Exam 3: Describing Data: Numerical Measures

A sample of single persons receiving social security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839 and $965. How many observations are below the median?

The mean, as a measure of central location would be inappropriate for which one of the following?

During the past six months, the purchasing agent bought: What is the weighted arithmetic mean price per ton?

The spread in the annual prices of stocks selling under $10 and those selling over $60 are to be compared. The mean price of the stocks selling under $10 is $5.25 and the standard deviation is $1.52. The mean price of those stocks selling over $60 is $92.50 and the standard deviation is $5.28. Why should the coefficient of variation be used to compare the dispersion in the prices? _______

A study is made of the commissions paid to furniture salespersons. If the variance is computed, it would be measured in _____________.

i. The sum of the deviations from the mean for the set of numbers 4, 9 and 5 will equal zero. ii. If there is an even number of ungrouped values, the median is found by arranging them from low to high and then determining the arithmetic mean of the two middle values. Iii) For salaries of $102,000, $98,000, $45,000, $106,000 and $101,000, the arithmetic mean would be an appropriate average.

The sum of the deviations of each value from the mean equals ______.

The weekly sales from a sample of ten computer stores yielded a mean of $25,900; a median $25,000 and a mode of $24,500. The shape of the distribution is_____________ .

A company's human resource department was interested in the average number of years that a person works before retiring. The sample of size 11 follows: -The median is______ .

Below is a summary of the size of homes for sale in Regina in 2005. The Empirical Rule would suggest that the middle 95% of the home sizes are between what two approximate values?

The lengths of stay on the cancer floor of Community Hospital were organized into a frequency distribution. The mean length was 28 days, the median 25 days and the modal length 23 days. The standard deviation was computed to be 4.2 days. The Pearson's coefficient of skewness is_______

The U.S. Department of Education reported that for the past seven years 4,033, 5,652, 6,407, 7,201, 8,719, 11,154, and 15,121 people received bachelor's degrees in computer and information sciences. What is the arithmetic mean annual number receiving this degree?

i. In a positively skewed distribution, the mean is always greater than the median. ii. In a negatively skewed distribution, the mode occurs at the peak of the curve. iii. In a negatively skewed distribution, the mode is greater than the median.

Which of the following measures of dispersion are based on deviations from the mean?

The ages of newly hired, unskilled employees were grouped into the following distribution: What is the median age?

Sometimes, data has two values that have the highest and equal frequencies. In this case, the distribution of the data can best be summarized as

A large group of inductees was given a mechanical aptitude and a finger dexterity test. The arithmetic mean score on the mechanical aptitude test was 200, with a standard deviation of 10. The mean and standard deviation for the finger dexterity test were 30 and 6 respectively. What is the relative dispersion in the two groups?

The weights of a sample of 100 boxes being shipped by Air France from Toronto to Paris are: -The standard deviation for nylon carpet is __________-.

Mr. and Mrs. Jones live in a neighbourhood where the mean family income is $45,000 with a standard deviation of $9,000. Mr. and Mrs. Smith live in a neighbourhood where the mean is $100,000 and the standard deviation is $30,000. What are the relative dispersions of the family incomes in the two neighbourhoods?

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. _________has the greater coefficient of variation?