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Measures of Central Tendency and Measures of Dispersion. Probability & Statistics Sections 2.3, 2.4. What does a standard deviation of 0 mean?. The mean is very low. The data values are all very close in value. The data values must all be the same. All the data values must be 0.
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Measures of Central Tendency and Measures of Dispersion Probability & Statistics Sections 2.3, 2.4
What does a standard deviation of 0 mean? • The mean is very low. • The data values are all very close in value. • The data values must all be the same. • All the data values must be 0.
If the sample variance is calculated and found to be s2 = 9, what is the standard deviation? If the sample variance is calculated and found to be s2 = 9, what is the standard deviation? • 3 • 3 or -3 • -3 • 81
Given the extension table below, find the sample standard deviation using the formula for the sample variance. Given the extension table below, find the sample standard deviation using the formula {image} for the sample variance. x {image} {image} 24 -10 100 37 3 9 34 0 0 45 11 121 30 -4 16 • 61.5 • 7.8 • 246 • 7.0
Which variable would most likely have a left-skewed distribution? • age of college students at local community college • heights of college students • grades on a very difficult statistics exam • age at which death occurs
Which of the following data sets does not have a mean of 3? • 3, 3, 3, 3, 3 • 0, 3, 3, 3, 6 • 1, 4, 2, 2, 6 • 3, 3, 3, 3, 5
What is the median of the data set {4, 7, 8, 2, 9}? • 2 • 6 • 8 • 7
Find the median age of the math department if the members' ages are: 30, 46, 50, 26, 70, 57 • 46 • 50 • 48 • 38
The histogram of 19 exam scores is given below. Estimate the median score. The histogram of 19 exam scores is given below. Estimate the median score. {image} • 60 • 65 • 70 • 75 • 80
Which set of numbers has a mean that is equal to its median? • 2, 3, 4, 2, 6 • 1, 6, 5, 4, 1 • 7, 1, 1, 2, 6 • 2, 2, 1, 1, 4
Which data set has a mode of 3? • 7, 7, 7, 5, 2 • 1, 1, 3, 3, 5 • 8, 3, 7, 3, 2 • 5, 5, 5, 1, 1
Consider the data set {11, 14, 6, 11, 3}. After a typographical error is discovered, the first 11 was changed to a 17. Which of the following would remain unchanged? • midrange • median • mean • mode
What word best describes a distribution whose mean is significantly larger than its median? • uniform • symmetric • right-skewed • left-skewed
Consider the weights (in pounds) of the five children at a local daycare center:24, 37, 34, 45, 30What is the range? • 6 • 21 • 23 • 10.5