Exam 3: Numerical Descriptive Techniques

The interquartile range will always exceed that of the range.

Pets Survey: A sample of 40 families were asked how many pets they owned. Their responses are summarized in the following table. -Explain what the mean, median, and mode tell you about this particular data set.

The first and second quartiles of a data set can never be equal.

Weights of Police Officers: The following data represent the weights in pounds of a sample of 25 police officers: 164, 148, 137, 157, 173, 156, 177, 172, 169, 165, 145, 168, 163, 162, 174, 152, 156, 168, 154, 151, 174, 146, 134, 140, and 171. -Determine the location and value of the lower quartile of the weights.

There are three measures of central location; the mean, the ____________________ and the ____________________.

The interquartile range is found by taking the difference between the 1st and 3rd quartiles and dividing that value by 2.

If the supermarket begins each morning with a supply of 67 containers of milk, how often will demand exceed the supply? (Give a percentage.)

In a perfectly symmetric distribution, which of the following statements is false?

Weights of Police Officers: The following data represent the weights in pounds of a sample of 25 police officers: 164, 148, 137, 157, 173, 156, 177, 172, 169, 165, 145, 168, 163, 162, 174, 152, 156, 168, 154, 151, 174, 146, 134, 140, and 171. -Determine the location and value of the second quartile of the weights.

Ages of Volunteers: The following data represent the ages in years of a sample of 25 volunteers from a charitable organization: 31, 43, 56, 23, 49, 42, 33, 61, 44, 28, 48, 38, 44, 35, 40, 64, 52, 42, 47, 39, 53, 27, 36, 35, and 20. -Compute the coefficient of variation, and express the number in the appropriate unit.

Find the median number of workers.

Strip Mall Rent: Monthly rent data in dollars for a sample of 10 stores in a small town in South Dakota are as follows: 220, 216, 220, 205, 210, 240, 195, 235, 204, and 250. -What is the mode?

The sample mean is denoted by ____________________ and the population mean is denoted by ____________________.

A perfect straight line sloping upward would produce a correlation coefficient value of 1.0.

The range, variance, standard deviation, and coefficient of variation are to be used only on ____________________ data.

Another word for the mean of a data set is the ____________________.

If the coefficient of correlation r = -.81, the standard deviations of x and y are 20 and 25, respectively, then cov(x, y) must be -405.0.

When the standard deviation is expressed as a percentage of the mean, the result is the coefficient of correlation.

Longevity and Salary: A sample of eight observations of variables x (years of experience) and y (salary in $1,000s) is shown below: -A.Calculate the coefficient of correlation, and comment on the relationship between x and y. B.Give a possible reason that the correlation is negative.

Hours Worked per Week: The following data represent the hours worked per week of a sample of 25 employees from a government department: 31, 43, 56, 23, 49, 42, 33, 61, 44, 28, 48, 38, 44, 35, 40, 64, 52, 42, 47, 39, 53, 27, 36, 35, and 20. -Find the modal hours.