Exam 3: Numerical Descriptive Measures

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,what type of shape does the distribution of the sample appear to have?

An economics lecturer bases his final grade on tutorial work,two mid-semester tests,and a final examination.The tutorial work counts 10% toward the final grade,while each mid-semester test counts 25%.The remaining portion consists of the final examination.If a student scored 95% in tutorial work,70% on the first mid-semester test,96% on the second mid-semester test,and 72% on the final exam,his final average is 79.8%.

If the mean is equal to the median,the distribution is symmetrical or has zero skewness.

The interquartile range is a measure of variation or dispersion in a set of data.

Instruction 3-10 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 3-10,you will expect a decrease in the amount of energy drink consumed within the week prior to the exam to be associated with ________.

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.

Which of the arithmetic mean,median,mode,and geometric mean are resistant measures of central tendency?

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 variance of the customs data is ________.

The Z score of an observation can never be negative.

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 1 99 2 0023 2 567 3 034 3 568 4 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 third quartile of the number of vitamin supplements sold in this sample is ________.

Certain rules can be applied when calculating the quartiles.Which of the following is NOT true about these rules.

Which measure of central tendency can be used for both numerical and categorical variables?

In exploratory data analysis,a boxplot can be used to illustrate the median,quartiles,and extreme values.

The median of the values 3.4,4.7,1.9,7.6,and 6.5 is 1.9.

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 third quartile of the ages of the uninsured senior citizens.

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 1 99 2 0023 2 567 3 034 3 568 4 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 3-5 The rate of return of a listed Australian 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 Instruction 3-5,compute the arithmetic mean rate of return.

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

Instruction 3-10 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 3-10,how will you classify the linear relationship between the exam scores and the number of energy drinks consumed?

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,construct a box-and-whisker plot for the rate of return.