Exam 3: Numerical Descriptive Measures

In a right-skewed distribution

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%. -You were told that the 1ˢᵗ, 2ⁿᵈ and 3ʳᵈ quartiles of female students' weight at a major university are 95 lbs, 125 lbs, and 138 lbs. What percentage of the students weigh more than 125 lbs?

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

The line drawn within the box of the boxplot always represents the arithmetic mean.

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 standard deviation of the number of vitamin supplements sold in this sample is ________.

According to the empirical rule, if the data form a "bell-shaped" normal distribution, ________ percent of the observations will be contained within 2 standard deviations around the arithmetic mean.

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 coefficient of variation of the number of vitamin supplements sold in this sample is ________ percent.

TABLE 3-2 The data below represent the amount of grams of carbohydrates in a serving of breakfast cereal in a sample of 11 different servings. 11 15 23 29 19 22 21 20 15 25 17 -Referring to Table 3-2, the coefficient of variation of the carbohydrate amounts is ________ percent.

TABLE 3-12 Given below are the rating and performance scores of 15 laptop computers. Performance Score 115 191 153 194 236 184 184 216 185 183 189 202 192 141 187 Overall Rating 74 78 79 80 84 76 77 92 83 78 77 78 78 73 77 -Referring to Table 3-12, how will you classify the linear relationship between the performance scores and the rating?

Which of the following is not sensitive to extreme values?

The larger the Z score, the farther is the distance from the value to the median.

The Z score of a value can never be negative.

The Z score of a value measures how many standard deviations the value is from the mean.