Exam 3: Numerical Descriptive Measures

In a set of numerical data, the value for Q₂ is always halfway between Q₁ and Q₃.

The smaller the spread of scores around the arithmetic mean,

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 observations is 838, the sum of the squares of the observations is 20,684, and the sum of the squared differences between each observation and the mean is 619.89. -Referring to Table 3-4, the first quartile of the customs data is ________.

In a perfectly symmetrical distribution

TABLE 3-9 The following table represents the assets in billions of dollars of the five largest bond funds. -Referring to Table 3-9, what are the variance and standard deviation for this population?

TABLE 3-7 In the 2009-2010 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 2008-2009 academic year for a sample of 10 public universities were as follows: $1589, $593, $1223, $869, $423, $1720, $708, $1425, $922 and $308. -Referring to Table 3-7, what is the standard deviation of the change in the cost?

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

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 observations is 448, the sum of the squares of the observations is 13,356, and the sum of the squared differences between each observation and the mean is 812. -Referring to Table 3-3, the range of the number of vitamin supplements sold in this sample is ________.

In a right-skewed distribution

In right-skewed distributions, the distance from Q₃ to the largest observation exceeds the distance from the smallest observation to Q₁.

TABLE 3-7 In the 2009-2010 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 2008-2009 academic year for a sample of 10 public universities were as follows: $1589, $593, $1223, $869, $423, $1720, $708, $1425, $922 and $308. -Referring to Table 3-7, are the data skewed? If so, how?

Which of the following statements about the median is not true?

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 observations is 448, the sum of the squares of the observations is 13,356, and the sum of the squared differences between each observation and the mean is 812. -Referring to Table 3-3, the five-number summary of the data in this sample consists of ________, ________, ________, ________, ________.

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 observations is 448, the sum of the squares of the observations is 13,356, and the sum of the squared differences between each observation and the mean is 812. -Referring to Table 3-3, the first quartile of the number of vitamin supplements sold in this sample is ________.

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

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. -Referring to Table 3-2, the coefficient of variation of the carbohydrate amounts is ________ percent.

TABLE 3-1 Health care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years of age whose net worth is too high to qualify for Medicaid and have no private health insurance. The ages of 25 uninsured senior citizens were as follows: -Referring to Table 3-1, calculate the variance of the ages of the uninsured senior citizens correct to the nearest hundredth of a year squared.

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 3-2 The data below represent the amount of grams of carbohydrates in a serving of breakfast cereal in a sample of 11 different servings. -Referring to Table 3-2, the range in the carbohydrate amounts is ________ grams.

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. -Referring to Table 3-2, the variance of the carbohydrate amounts is ________ (grams squared).