Exam 3: Numerical Descriptive Measures

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

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 variance of the carbohydrate amounts is ________ (grams squared).

The standard deviation is a measure of how a set of data is clustered or distributed around its mean.

The rate of return for Microsoft's stock over a seven year period is 0.527,0.145,0.684,1.146,0.564,0.883 and 0.436.The geometric mean rate of return is ________.

In a sample of size 40,the sample mean is 15.In this case,the sum of all observations in the sample is Σ X_i = 600.

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,you will expect a decrease in the performance score of one laptop computer to be associated with ________.

The vertical line drawn within the box of the boxplot always represents the median.

Instruction 3-8 Given below is the frequency distribution of the number of defective tomatoes in 50 different shipments. Defective Items Frequency 0 but less than 5 35 5 but less than 10 7 10 but less than 15 5 15 but less than 20 2 20 but less than 25 1 25 but less than 30 0 -Referring to Instruction 3-8,what is the approximate standard deviation?

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

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

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,what is the range of the rate of return?

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

The coefficient of variation is expressed as a percentage.

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

The interquartile range is a measure of central tendency in a set of data.

In general,which of the following descriptive summary measures cannot be easily approximated from a boxplot?

In a perfectly symmetrical distribution

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

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 3-4 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 ________.