Exam 3: Describing Data: Numerical Measures

A sample of five full service gasoline stations, each carrying three grades of gasoline, was taken and the price per liter (to the nearest cent) was recorded for each grade of gasoline, as shown in the table below. What is the mean price of Super Unleaded gas? _______.

Samples of the wires coming off the production line were tested for tensile strength. The statistical results (in PSI) were: According to the Empirical Rule, the middle 95 percent of the wires tested between approximately what two values?

What is the smallest measure of central location in a positively skewed distribution? ___________

For any distribution, there are an equal number of values above and below the mean.

A bottling company offers three kinds of delivery service - instant, same day and within five days. The profit per delivery varies according to the kind of delivery. The profit for an instant delivery is less than the other kinds because the driver has to go directly to a grocery store with a small load and return to the bottling plant. To find out what effect each type of delivery has on the profit picture, the company summarized the data in the following table based on deliveries for the previous quarter. What is the weighted mean profit per delivery?

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

In a frequency distribution, what measure of central location is used for the class with the largest number of observations? ______________

Which measure of dispersion disregards the algebraic signs (plus and minus) of each difference between X and the mean?

What are the similarities and differences between the range and the standard deviation?

The net annual sales of a sample of small retail clothing stores were organized into the following relative frequency distribution. What is the mean net sales (in $millions)?

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

Rank the measures of dispersion in terms of their relative computational difficulty from least to most.

The weights (in grams) of the contents of several small bottles are 4, 2, 5, 4, 5, 2 and 6. What is the sample variance?

A sample of five full service gasoline stations, each carrying three grades of gasoline, was taken and the price per liter (to the nearest cent) was recorded for each grade of gasoline, as shown in the table below. What is the mean price of Unleaded gas? _______.

The capacities of several metal containers are: 38, 20, 37, 64, and 27 liters. What is the range in liters? ____.

In the calculation of the arithmetic mean for grouped data, which value is used to represent all the values in a particular class?

The lengths of time (in minutes) several underwriters took to review applications for similar insurance coverage are: 50, 230, 52 and 57. What is the median length of time required to review an application?

The value that occurs most often in a set of data is called the ____.

If a set of observations contains an extreme value and none of the observations repeat themselves, what is the most representative measure of central location? _____________

A population consists of all the weights of all defensive tackles on Sociable University's football team. They are: Johnson, 204 pounds; Patrick, 215 pounds; Junior, 207 pounds; Kendron, 212 pounds; Nicko, 214 pounds; and Cochran, 208 pounds. What is the population standard deviation (in pounds)?