Exam 3: Descriptive Statistics: Numerical Measures

Jason, a freshman at a local college, just completed 15 credit hours. His grade report is presented below. The local university uses a 4 point grading system, i.e., A = 4, B = 3, C = 2, D = 1, F = 0. Compute Jason's semester grade point average.

The flashlight batteries produced by one of the northern manufacturers are known to have an average life of 60 hours with a standard deviation of 4 hours. Use Chebyshev's theorem to answer the following questions. a.At least what percentage of flashlights will have a life of 54 to 66 hours? b.At least what percentage of the batteries will have a life of 52 to 68 hours? c.Determine an interval for the lives of the batteries that will be true for at least 80% of the batteries. (Hint: First compute the Z-score.)

Which of the following symbols represents the size of the sample

The sample variance

Exhibit 3-1 The following data show the number of hours worked by 200 statistics students. -Refer to Exhibit 3-1. The relative frequency of students working 9 hours or less

In the fall semester of 2009, the average Graduate Management Admission Test (GMAT) of the students at UTC was 500 with a standard deviation of 80. In the fall of 2010, the average GMAT was 560 with a standard deviation of 84. Which year's GMAT scores show a more dispersed distribution?

In 2012, the average donation to the Help Way was $225 with a standard deviation of $45. In 2013, the average donation was $400 with a standard deviation of $60. In which year did the donations show a more dispersed distribution?

The last semester grades of Nancy, a freshman at a local college are shown below. The local university uses a 4 point grading system, i.e., A = 4, B = 3, C = 2, D = 1, F = 0. Compute Nancy's semester grade point average.

Which of the following is not a measure of central location?

The numerical value of the standard deviation can never be

The geometric mean of 1, 2, 4, and 10 is

Descriptive statistics for the closing stock prices of two companies for several trading periods are shown below. a.Which company's stock price has a more dispersed distribution? Explain. Show your complete work and support your answer. b.Compare the Skewness' of the two and explain what is indicated.

The interquartile range is used as a measure of variability to overcome what difficulty of the range?

The measure of dispersion that is influenced most by extreme values is

The variance of a sample was reported to be 81. The report indicated that = 972. What has been the sample size?

When computing the mean of a set of values x_i, the value of $\Sigma$ x_i

The following data represent the daily supply (y in thousands of units) and the unit price (x in dollars) for a product. a.Compute and interpret the sample covariance for the above data. b.Compute the standard deviation for the daily supply. c.Compute the standard deviation for the unit price. d.Compute and interpret the sample correlation coefficient.

Aubree, a college freshman, took 15 hours her first semester. Below is her grade report. Aubree's university uses a 4-point grading system, i.e., A=4, B=3, C=2, D=1, F=0. a.Compute Aubree's grade point average at the end of the semester. b.The next semester, Aubree retakes physics and makes a B. If this B replaces her old grade (D), what would her revised GPA be? (Assume the only class she took her second semester was physics.) (Round to the nearest hundredth.)

The heights (in inches) of 25 individuals were recorded and the following statistics were calculated mean = 70 Range = 20 Mode = 73 Variance = 784 Median = 74 The coefficient of variation equals

The following frequency distribution shows the GMAT scores of a sample of MBA students: For the above data, compute the mean GMAT score.