Exam 3: Numerical Descriptive Measures

Instruction 3-4 The ordered array below represents the number of cargo manifests approved by customs inspectors at the Port of Brisbane 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 Instruction 3-4,the median of the customs data is _____________ .

Instruction 3-2 The data below represents 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 Instruction 3-2,the standard deviation of the carbohydrate amounts is_____________ grams.

In a perfectly symmetrical distribution

Instruction 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 than 0.0 3 0.0 but less than 0.1 5 0.1 but less than 0.2 6 0.2 but less than 0.3 10 0.3 but less than 0.4 6 -Referring to Instruction 3-7,what is the approximate variance?

Instruction 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 568 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 Instruction 3-3,the median number of vitamin supplements sold in this sample is_____________ .

The smaller the spread of scores around the arithmetic mean,the smaller the coefficient of variation and the smaller the standard deviation.

In a data set with 20 items,the median would be the average of the_________ items in the ordered array.

Instruction 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 568 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 Instruction 3-3,the arithmetic mean of the number of vitamin supplements sold in this sample is _____________ .

Instruction 3-15 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-grams energy drinks consumed by 10 college students within a week prior to the exam. Exam Scores 75 92 84 64 64 86 81 61 73 93 Number of Drinks 5 3 2 4 2 7 3 0 1 0 -Referring to Instruction 3-15,what is the sample covariance between the exam scores and the number of energy drinks consumed?

Instruction 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 who 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 Instruction 3-1,calculate the arithmetic mean age of the uninsured senior citizens to the nearest hundredth of a year.

Instruction 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 Instruction 3-6,compute the arithmetic mean rate of return.

None of the measures of variation (the range,interquartile range,standard deviation and variance)can ever be negative.

In a boxplot,the box portion represents the data between the _____________ quartile values.

When preparing data analysis,you should document

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?

When extreme values are present in a set of data,which of the following descriptive summary measures are most appropriate?

Instruction 3-2 The data below represents 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 Instruction 3-2,construct a box and whisker plot for the carbohydrate amounts.

The more concentrated,or homogeneous,the data,the smaller the range,interquartile range,variance and standard deviation.

Instruction 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 who 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 Instruction 3-1,identify the interquartile range of the ages of the uninsured senior citizens.

The Z score of an observation can never be negative.