Exam 3: Describing Data: Numerical Measures

The standard deviation is the positive square root of the variance.

Fifteen accounting majors had an average grade of 90 on a finance exam. Seven marketing majors averaged 85, while ten finance majors averaged 93 on the same exam. What is the weighted mean for the 32 students taking the exam?

Three persons earn $8 an hour, six earn $9 an hour, and one earns $12 an hour. The weighted mean hourly wage is $9.

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

The geometric mean is the nth root of n observations.

The variance is the mean of the sum of the squared deviations between each observation and the median.

Coastal Carolina University recently surveyed a sample of students to determine how far they lived from campus. The results are shown below. Compute the standard deviation.

In a departmental review of employee performance, 3 employees were scored a 4 (excellent performance), 5 employees were scored a 3 (average performance), and 1 employee was scored a 1 (below average performance). To compute a weighted mean, what are the weights? ______________________

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

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. What is the shape of the distribution? __________________

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 Plus gas? _______.

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

What does the sum of the deviations of each value from the mean equal? ____________________________________

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?

What is the positive square root of the variation? ________

What measure of central location uses all of the observations in its calculation? _____________

Five students were given a page of problems with instructions to solve as many as they could in one hour. The 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? ________.

For the most recent seven years, the U.S. Department of Education reported the following number of bachelor's degrees awarded in computer science: 4,033; 5,652; 6,407; 7,201; 8,719; 11,154; 15,121. What is the annual arithmetic mean number of degrees awarded?

The ages of all the patients in the isolation ward of the hospital are 38, 26, 13, 41 and 22. What is the population variance?

For a sample of similar sized all-electric homes, the March electric bills were (to the nearest dollar): $212, $191, $176, $129, $106, $92, $108, $109, $103, $121, $175 and $194. What is the range?