Exam 3: Numerical Descriptive Measures

In a right-skewed distribution

In perfectly symmetrical distributions,which of the following is NOT a correct statement?

Instruction 3-9 Given below are the rating and performance scores of 15 laptop computers. Performance 115 191 153 194 236 184 184 216 185 183 189 202 192 141 Overall 74 78 79 80 84 76 77 92 83 78 77 78 78 73 Rating -Referring to Instruction 3-9,how will you classify the linear relationship between the performance scores and the rating?

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 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,what is the sample correlation coefficient between the exam scores and the number of energy drinks consumed?

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

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

As a general rule,an observation is considered an extreme value if its Z score is less than 3.

According to the empirical rule,if the data form a "bell-shaped" normal distribution,________ percent of the observations will be contained within 1 standard deviation around the arithmetic mean.

As a general rule,an observation is considered an extreme value if its Z score is greater than 3.

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 third quartile of the customs data is ________.

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 standard deviation of the ages of the uninsured senior citizens correct to the nearest hundredth of a year.

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 five-number summary of the data in this sample consists of ________,________,________,________,________.

As a general rule,an observation is considered an extreme value if its Z score is greater than -3.

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,construct a boxplot of this sample.

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

In a boxplot,the box portion represents the data between the first and third quartile values.

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.

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. $\text{11 15 23 29 19 22 21 20 15 25 17}$ -Referring to Instruction 3-2,the interquartile range in the carbohydrate amounts is ________ grams.

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 first quartile of the ages of the uninsured senior citizens.