Stats Section 3

Statements about the proportion of data values that must be within a specified number of standard deviations of the mean can be made using a. Chebyshev's theorem. b. The empirical rule. c. A five-number summary. d. Percentiles.

A. Chebyshev's theorem

Which of the following is not a measure of variability? a. Mode b. Standard deviation c. Range d. Interquartile range

A. Mode

When n-1 is used in the denominator to compute variance, a. the data set is a sample. b. the data set is a population. c. the data set could be either a sample or a population. d. the data set is from a census.

A. The data set is a sample

The variance of a sample of 169 observations equals 576. The standard deviation of the sample equals a. 13. b. 24. c. 576. d. 28,561.

B. 24

The value which has half of the observations above it and half the observations below it is called the a. range. b. median. c. mean. d. mode.

B. Median

Which of the following is not a measure of variability? a. The range b. The 50th percentile c. The standard deviation d. The interquartile range

B. The 50th Percentile

The most frequently occurring value of a data set is called the a. range. b. mode. c. mean. d. median.

B. ode

The geometric mean of 1, 3, 5, and 6 is a. 15.0. b. 5.0. c. 3.08. d. 3.75.

C. 3.08

The variance of a sample was reported to be 144. The report indicated that = 7200. What is the sample size? a. 49 b. 50 c. 51 d. 52

C. 51

. A researcher has collected the following sample data. The mean of the sample is 5. 3 5 12 3 2 The interquartile range is a. 2. b. 2.25. c. 6. d. 9.

C. 6. Find median, then find difference between medians on both sides. That = IQR

. The empirical rule states that, for data having a bell-shaped distribution, the percentage of data values being within one standard deviation of the mean is approximately a. 33%. b. 50%. c. 68%. d. 95%

C. 68%

The variance of a sample of 81 observations equals 64. The standard deviation of the sample equals a. 9. b. 4096. c. 8. d. 6561.

C. 8

The coefficient of correlation a. is the same as the coefficient of determination. b. can be larger than 1. c. cannot be larger than 1. d. cannot be negative

C. CANNOT be larger than 1

The median is a measure of a. relative dispersion. b. absolute dispersion. c. central location. d. relative location.

C. Central Location

Which of the following is a measure of variability? a. Percentiles b. Quartiles c. Interquartile range d. Geometric mean

C. Interquartile Range

The numerical value of the standard deviation can never be a. larger than the variance. b. zero. c. negative. d. smaller than the variance.

C. Negative

The measure of variability that is influenced most by extreme values is a. the variance. b. the standard deviation. c. the range. d. the interquartile range.

C. The range

When a percentage of the smallest and largest values are deleted from a data set, the mean of the remaining data values is the a. geometric mean. b. weighted mean. c. trimmed mean. d. interquartile mean.

C. Trimmed Mean

A mean computed in such a way that each data value is given a weight reflecting its importance is referred to as a a. geometric mean. b. trimmed mean. c. weighted mean. d. balanced mean.

C. Weighted Mean

The geometric mean of 2, 4, 8 is a. 4.67. b. 5.0. c. 16. d. 4.0.

D. 4.0 (2*4*8 and then take the cubed root ((based off of how many numbers there are, 3 then cubed root, two then square root)

. A box plot is a graphical representation of data that is based on a. the empirical rule. b. z-scores. c. a histogram. d. a five number summary

D. A five number Summary

Which of the following statements about financial growth factors using the geometric mean is untrue? a. The growth factor cannot be less than zero. b. A growth factor less than 1 indicates negative growth. c. A growth factor greater than 2 indicates more than 100 percent growth. d. A growth factor greater than 0 indicates positive growth.

D. A growth factor greater than 0 indicates positive growth

Growth factors for the population of Atlanta in the past five years have been 1, 2, 3, 4, and 5. The geometric mean is a. 15. b. .sq rt 15 c. .sq rt 120 d. .fifth root:

D. Its fifth root

Which of the following symbols represents the size of the population? a. σ2 b. σ c. μ d. N

D. N

For data skewed to the left, the skewness is a. less than .5. b. less than 1. c. less than the mean. d. negative.

D. Negative

. From a population of size 400, a random sample of 40 items is selected. The median of the sample a. must be 200, since 400 divided by 2 is 200. b. must be 10, since 400 divided by 40 is 10. c. must be equal to the median of population, if the sample is truly random. d. none of these alternatives is correct.

D. None of these alternatives is corect

. Given the following information: Standard deviation = 8 Coefficient of variation = 64% The mean would then be a. 12.5. b. 8. c. 0.64. d. 1.25

a. 12.5

The variance of the sample a. can never be negative. b. can be negative. c. cannot be zero. d. cannot be less than one.

a. Can never be negative

The closing stock price of MNM Corporation for the last 7 trading days is shown below. Day Stock Price 1 84 2 87 3 84 4 88 5 85 6 90 7 91 The variance is: a. 2.828. b. 8. c. 9. d. 81.

b. 8 The formula of population variance is sigma squared equals the sum of x minus the mean squared divided by n.