FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 4: Numerical Descriptive Techniques

Show Answer

Share

---

All types

Filters

Study Flashcards

Question 121

Short Answer

Review LaterAdd Note

Review Later

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. -{Hours Worked per Week Narrative} Find the modal hours.

Correct Answer

verified

Modes are ...

View Answer

Show Answer

Question 122

True/False

Review LaterAdd Note

Review Later

A population with 200 elements has a variance of 20.From this information, it can be shown that the population standard deviation is 10.

A) True
B) False

Correct Answer

verified

Show Answer

Question 123

Short Answer

Review LaterAdd Note

The ____________________ is the least desirable of all the measures of central location.

The coefficient of variation allows us to compare two sets of data based on different measurement units.

Salaries of Employees The following data represent the yearly salaries (in thousands of dollars) of a sample of 13 employees of a firm: 26.5, 23.5, 29.7, 24.8, 21.1, 24.3, 20.4, 22.7, 27.2, 23.7, 24.1, 24.8, and 28.2. -{Salaries of Employees Narrative} Compare the mean salary with the median salary and use them to describe the shape of the distribution.

A sample of 12 construction workers has a mean age of 25 years.Suppose that the sample is enlarged to 14 construction workers, by including two additional workers having common age of 25 each.Find the mean of the sample of 14 workers.

Yearly Donations The following data represent the yearly donations (in thousands of dollars) of a sample of 13 benefactors: 26.5, 23.5, 29.7, 24.8, 21.1, 24.3, 20.4, 22.7, 27.2, 23.7, 24.1, 24.8, and 28.2. -{Yearly Donations Narrative} a. Describe the shape of distribution of donations based on the values of the quartiles. b. Give a possible reason for the shape of this data set, in terms of donations.

In a histogram, the proportion of the total area which must be to the right of the mean is:

Salaries of Employees The following data represent the yearly salaries (in thousands of dollars) of a sample of 13 employees of a firm: 26.5, 23.5, 29.7, 24.8, 21.1, 24.3, 20.4, 22.7, 27.2, 23.7, 24.1, 24.8, and 28.2. -{Salaries of Employees Narrative} Compute the mean salary.

According to Chebysheff's Theorem, at least 93.75% of observations should fall within 4 standard deviations of the mean.

If the standard deviation of x is 18, the covariance of x and y is 120, the coefficient r = 0.90, then the standard deviation of y is 54.87.

Which of the following statements about the mean is not always correct?

The value of the mean times the number of observations equals the sum of the observations.

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. -{Ages of Volunteers Narrative} Compute the range of the data and express the number in the appropriate unit.

The ____________________ is not as sensitive to extreme values as the ____________________.

Computers The following data represent the number of computers owned by a sample of 10 families from Chicago: 4, 2, 1, 1, 5, 3, 0, 1, 0, and 2. -{Computers Narrative} Compute the mean number of computers.

The ____________________ of a linear relationship is hard to interpret from the covariance, but it is easy to interpret from the correlation.

According to the Empirical Rule, if the data form a bell shaped normal distribution approximately ____________________ percent of the observations will be contained within 3 standard deviations around the mean.

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. -{Strip Mall Rent Narrative} Compute the sample monthly average rent.

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