Exam 3: Numerical Descriptive Measures

TABLE 3-3 The ordered array below represents the number of vitamin supplements sold by a health food store in a sample of 16 days. 19, 19, 20, 20, 22, 23, 25, 26, 27, 30, 33, 34, 35, 36, 38, 41 Note: For this sample, the sum of the values is 448, and the sum of the squared differences between each value and the mean is 812. -Referring to Table 3-3, what type of shape does the distribution of the sample appear to have?

TABLE 3-7 In a recent academic year, many public universities in the United States raised tuition and fees due to a decrease in state subsidies. The change in the cost of tuition, a shared dormitory room, and the most popular meal plan from the previous academic year for a sample of 10 public universities were as follows: $1,589, $593, $1,223, $869, $423, $1,720, $708, $1425, $922 and $308. -Referring to Table 3-7, what is the interquartile range of the change in the cost?

TABLE 3-3 The ordered array below represents the number of vitamin supplements sold by a health food store in a sample of 16 days. 19, 19, 20, 20, 22, 23, 25, 26, 27, 30, 33, 34, 35, 36, 38, 41 Note: For this sample, the sum of the values is 448, and the sum of the squared differences between each value and the mean is 812. -Referring to Table 3-3, the interquartile range of the number of vitamin supplements sold in this sample is ________.

In a sample of size 40, the sample mean is 15. In this case, the sum of all observations in the sample is Xᵢ = 600.

TABLE 3-6 The rates of return of an Internet Service Provider over a 10 year period are: 10.25%, 12.64%, 8.37%, 9.29%, 6.23%, 42.53%, 29.23%, 15.25%, 21.52%, -2.35%. -Referring to Table 3-6, construct a boxplot for the rate of return

In a set of numerical data, the value for Q₃ can never be smaller than the value for Q₁.

According to the empirical rule, if the data form a "bell-shaped" normal distribution, ________ percent of the observations will be contained within 1 standard deviation around the arithmetic mean.

TABLE 3-13 Energy drink consumption has continued to gain in popularity since the 1997 debut of Red Bull, the current leader in the energy drink market. Given below are the exam scores and the number of 12-ounce energy drinks consumed within a week prior to the exam of 10 college students. -Referring to Table 3-13, what is the sample covariance between the exam scores and the number of energy drinks consumed?

A manufacturer of flashlight batteries took a sample of 130 batteries from a day's production and used them continuously until they were drained. The number of hours until failure are recorded. Given below is the boxplot of the number of hours it took to drain each of the 130 batteries. The distribution of the number of hours is

TABLE 3-12 Given below are the rating and performance scores of 15 laptop computers. -Referring to Table 3-12, what is the sample correlation coefficient between the performance scores and the rating?

TABLE 3-5 The rates of return of a Fortune 500 company over the past 15 years are: 3.17%, 4.43%, 5.93%, 5.43%, 7.29%, 8.21%, 6.23%, 5.23%, 4.34%, 6.68%, 7.14%, -5.56%, -5.23%, -5.73%, -10.34% -Referring to Table 3-5, compute the arithmetic mean rate of return per year.

TABLE 3-3 The ordered array below represents the number of vitamin supplements sold by a health food store in a sample of 16 days. 19, 19, 20, 20, 22, 23, 25, 26, 27, 30, 33, 34, 35, 36, 38, 41 Note: For this sample, the sum of the values is 448, and the sum of the squared differences between each value and the mean is 812. -Referring to Table 3-3, the range of the number of vitamin supplements sold in this sample is ________.

TABLE 3-13 Energy drink consumption has continued to gain in popularity since the 1997 debut of Red Bull, the current leader in the energy drink market. Given below are the exam scores and the number of 12-ounce energy drinks consumed within a week prior to the exam of 10 college students. -Referring to Table 3-13, for a student who has consumed a high number of energy drinks within the week prior to the exam, you will expect his/her exam score to

As a general rule, a value is considered an extreme value if its Z score is less than -3.

TABLE 3-4 The ordered array below represents the number of cargo manifests approved by customs inspectors of the Port of New York in a sample of 35 days: 16, 17, 18, 18, 19, 20, 20, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 25, 25, 26, 26, 26, 27, 28, 28, 29, 29, 31, 31, 32, 32 Note: For this sample, the sum of the values is 838, and the sum of the squared differences between each value and the mean is 619.89. -Referring to Table 3-4, the coefficient of variation of the customs data is ________ percent.

The median of a data set with 20 items would be the average of the 10th and the 11th items in the ordered array.

The coefficient of variation is a measure of relative variation.

TABLE 3-7 In a recent academic year, many public universities in the United States raised tuition and fees due to a decrease in state subsidies. The change in the cost of tuition, a shared dormitory room, and the most popular meal plan from the previous academic year for a sample of 10 public universities were as follows: $1,589, $593, $1,223, $869, $423, $1,720, $708, $1425, $922 and $308. -Referring to Table 3-7, what is the mean and median change in the cost?

In right-skewed distributions, which of the following is the correct statement?

According to the Chebyshev rule, at least 75% of all observations in any data set are contained within a distance of how many standard deviations around the mean?