Exam 3: Numerical Descriptive Measures

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 standard deviation?

The geometric mean is useful in measuring the rate of change of a variable over time.

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 first quartile of the number of vitamin supplements sold in this sample is ________.

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 interquartile range of the number of vitamin supplements sold in this sample is ________.

When preparing data analysis,you should document

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,construct a box and whisker plot for the carbohydrate amounts.

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 covariance between the exam scores and the number of energy drinks consumed?

The coefficient of variation is a measure of central tendency in the data.

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 coefficient of variation of the customs data is ________ percent.

Instruction 3-3B 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 -Referring to Instruction 3-3B,construct a box-and-whisker plot for the data in this sample.

Summary measures which are not influenced by extreme values,are called ________.

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

A boxplot is a graphical representation of a five-number summary.

The more spread out,or dispersed,the data,the larger the range,interquartile range,variance and standard deviation.

If the mean is greater than the median,the distribution is likely to be negative or left skewed.

Which of the following is the easiest to compute?

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 box-and-whisker plot.

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.

According to the empirical rule,if the data form a "bell-shaped" normal distribution,________ percent of the observations will be contained within 3 standard deviations around the arithmetic mean.

When preparing statistical information,it is important to be conscious of errors in both the objectivity of your analysis and the subjectivity of your interpretation.