Exam 3: Numerical Descriptive Measures

$\text { TABLE 3-7 }$ Given below is the frequency distribution of the 12-month rate of return achieved by 30 stocks. 12- month Rate of Return Number of Funds -0.10 but less th an 0.0 3 0.0 but less th an 0.1 5 0.1 but less th 0.2 6 0.2 but less th 0.3 10 0.3 but less than 0.4 6 -Referring to Table 3-7, what is the approximate standard deviation?

TABLE 3-12 The population of eight analysts at a software firm were asked to estimate the reuse rate when developing a new software system. The following data are given as a percentage of the total code written for a software system that is part of the reuse database. 50, 62.5, 37.5, 75.0, 45.0, 47.5, 15.0, 25.0 -Referring to Table 3-12, what is the mean percentage of the total code that is part of the reuse database?

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 interquartile range in the carbohydrate amounts is _____grams.

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: 60 61 62 63 64 65 66 68 68 69 70 73 73 74 75 76 76 81 81 82 86 87 89 90 92 -Referring to Table 3-1, calculate the coefficient of variation of the ages of the uninsured senior citizens.

TABLE 3-6 The rate 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, compute the geometric mean rate of return.

The coefficient of variation measures variability in a data set relative to the size of the arithmetic mean.

The smaller the spread of scores around the arithmetic mean

TABLE 3-4 The stem-and-leaf display below represents the number of cargo manifests approved by customs inspectors of the Port of New York in a sample of 35 days. Stem Leaves 1 67889 2 0011122223333444 2H 5566678899 3 1122 Note (1): 1H means the "high teens" - 15, 16, 17, 18, or 19; 2L means the "low twenties" - 20, 21, 22, 23, or 24; 2H means the "high twenties" - 25, 26, 27, 28, or 29, etc. Note (2): 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_____ .

The Z scores can be used to identify outliers.

$\text { TABLE 3-2 }$ The data below represent the amount of grams of carbohydrates in a serving of breakfast cereal in a sample of 11 different servings. $11\quad15\quad23\quad29\quad19\quad22\quad21\quad20\quad15\quad25\quad17$ -Referring to Table 3-2, the five-number summary of the carbohydrate amounts consists of_____,_____ ,_____ ,_____ , and ______.

The Z score of an observation can never be negative.

If the data set is approximately bell-shaped, the empirical rule will more accurately reflect the greater concentration of data close to the mean as compared to the Chebyshev rule.

If the distribution of a data set were perfectly symmetrical, the distance from Q1 to the median would always equal the distance from Q3 to the median in a boxplot.

$\text { TABLE 3-4 }$ The stem-and-leaf display below represents the number of cargo manifests approved by customs inspectors of the Port of New York in a sample of 35 days. Stem Leaves 1H 67889 2L 0011122223333444 2H 5566678899 3L 1122 Note (1): 1H means the "high teens" - 15, 16, 17, 18, or 19; 2L means the "low twenties" - 20, 21, 22, 23, or 24; 2H means the "high twenties" - 25, 26, 27, 28, or 29, etc. Note (2): 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 standard deviation of the customs data is _____.

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: 60 61 62 63 64 65 66 68 68 69 70 73 73 74 75 76 76 81 81 82 86 87 89 90 92 -Referring to Table 3-1, identify the third quartile of the ages of the uninsured senior citizens.

If a set of data is perfectly symmetrical, the arithmetic mean must be identical to the median.

TABLE 3-4 The stem-and-leaf display below represents the number of cargo manifests approved by customs inspectors of the Port of New York in a sample of 35 days. Stem Leaves 1 67889 2 0011122223333444 2 5566678899 3 1122 Note (1): 1H means the "high teens" — 15, 16, 17, 18, or 19; 2L means the "low twenties" — 20, 21, 22, 23, or 24; 2H means the "high twenties" — 25, 26, 27, 28, or 29, etc. Note (2): 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 3-3, the third quartile of the number of vitamin supplements sold in this sample is ____.

TABLE 3-3 The stem-and-leaf display below represents the number of vitamin supplements sold by a health food store in a sample of 16 days. Stem Leaves 1H 99 2L 0023 2H 567 3L 034 3H 4L 1 Note (1): 1H means the "high teens" - 15, 16, 17, 18, or 19; 2L means the "low twenties" - 20, 21, 22, 23, or 24; 2H means the "high twenties" - 25, 26, 27, 28, or 29, etc. Note (2): 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, what type of shape does the distribution of the sample appear to have?

In a perfectly symmetrical distribution

Which descriptive summary measures are considered to be resistant statistics?