The mean hours of sleep that students get per night is 7 hours, the standard deviation of hours of sleep is 1.7 hours, and the distribution is approximately normal. Complete the following sentence. For about 95 of students, nightly amount of sleep is between ______.
a. 5.3 and 8.7 hrs
b. 5 and 9 hrs
c. 3.6 and 10.4 hrs
d. 1.9 and 12.1 hrs
Q. 2By inspection, determine which of the following sets of numbers has the smallest standard deviation.
a. 2, 3, 4, 5
b. 4, 4, 4, 5
c. 0, 0, 5, 5
d. 5, 5, 5, 5
Q. 3Which of the following is true about the relationship between the standard deviation s and the range for a large bell-shaped data set?
a. The range is approximately 1/2 of a standard deviation.
b. The range is approximately 2 standard deviations.
c. The range is approximately 6 standard deviations.
d. The range is approximately 1/6 of a standard deviation
Q. 4The head circumference (in centimeters) of 15 college-age males was obtained, resulting in the following measurements: 55, 56, 56, 56.5, 57, 57, 57, 57.5, 58, 58, 58, 58.5, 59, 59, 63 . If the last measurement (63 cm's) were incorrectly recorded as 73, which one of the following statistics would change?
a. Q1 (1st quartile)
b. Standard deviation
c. Median
d. Q3 (3rd quartile)
Q. 5Which one of the following summary statistics is not a measure of the variation (spread) in a data set?
a. Median
b. Standard deviation
c. Range
d. Interquartile range
Q. 6Which of the following measures is not a measure of spread?
a. Variance
b. Standard deviation
c. Interquartile range
d. Median
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