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 following table. What is the mean price of super unleaded gas?

The square root of the variance is called the ______.

A stockbroker placed the following order for a customer: • 50 shares of Kaiser Aluminum at $104 a share • 100 shares of GTE at $25.25 a share • 20 shares of Boston Edison at $9.125 a share What is the weighted arithmetic mean price per share?

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

The mean monthly income of a group of college students is $500; the standard deviation is $50. According to Chebyshev's theorem, at least what percent of the incomes will lie between $400 and $600?

A disadvantage of using an arithmetic mean to summarize a set of data is that __________.

Which measures of central location are not affected by extremely small or extremely large values?

Assume a student received the following grades for the semester: History, B; Statistics, A; Spanish, C; and English,C. History and English are 5 credit-hour courses, Statistics a 4 credit-hour course, and Spanish a 3 credit-hour course. If 4 grade points are assigned for an A, 3 for a B, and 2 for a C, what is the weighted mean grade for the semester?

The mode is the value of the observation that appears most frequently.

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

A set of ordinal-, interval-, or ratio-level data may only have one mode.

The times (in minutes) that 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 standard deviation is the positive square root of the variance.

If a set of quantitative observations contains an extreme value, the most representative measure of central location would be the __________.

What are the similarities and differences between the mean, the median, and the mode?

What is the relationship between the variance and the standard deviation?

The distribution of a sample of the outside diameters of PVC pipes approximates a symmetrical, bell-shaped distribution. The arithmetic mean is 14.0 inches, and the standard deviation is 0.1 inches. About 68% of the outside diameters lie between what two amounts?

A sample of wires coming off the production line was tested for tensile strength. The statistical results (in PSI) were the following: According to the Empirical Rule, the middle 95% of the wires tested had a tensile strength between approximately what two values?

For a set of data arranged or sorted in numerical order, the value of the observation in the center is called the weighted mean.

Ten experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their ratings were: 34, 35, 41, 28, 26, 29, 32, 36, 38, and 40. What is the mean deviation of the ratings?