Distributions of Data

Use a graphing calculator to construct a histogram for the data, and use it to describe the shape of the distribution.

• Negatively Skewed

• Symmetric

• Positively Skewed

• Uniform

• Skewed so use the Mean and Standard Deviation.

  Mean: $36.70

  Standard Deviation: $18.58

• Symmetric so use the Mean and Standard Deviation.

  Mean: $36.70

  Standard Deviation: $18.58

• Skewed so use the Five Number Summary.

  Minimum: 5

  Quartile 1: 25

  Median: 35

  Quartile 3: 45

  Maximum: 95

• Symmetric so use the Five Number Summary.

  Minimum: 5

  Quartile 1: 25

  Median: 35

  Quartile 3: 45

  Maximum: 95

How many people have two or less books in their desk?

• 4

• 5

• 6

• 7

Many professional schools require applicants to take a standardized test. Suppose that 1000 students take such a test. Several weeks after the test, Pete recieves his score report: he got a 63, which placed him at the 73rd percentile. This means that

• Pete's score was below the median.

• Pete did worse than about 63% of the test takers.

• Pete did worse than about 73% of the test takers.

• Pete did better than about 73% of the test takers.

For the Normal distribution shown, the standard deviation is closest to

• 1

• 2

• 3

• 4

The average yearly snowfall in Chillyville is Normally distributed with a mean of 55 inches. If the snowfall in Chillyville exceeds 60 inches in 15% of the years, what is the standard deviation?

• 4.83 inches

• 8.93 inches

• 5.18 inches

• The standard deviation cannot be computed from the given information.

If the heights of American men follow the Normal distribution, and 99.7% have heights between 5'0'' and 7'0'', what is your estimate of the standard deviation of the height of American men?

• 1"

• 3"

• 4"

• 6"

Which of the following is NOT correct about the standard Normal distribution?

• The proportion of scores that satisfy 0

• The proportion of scores that satisfy z>-3.0 is 0.9938

• The proportion of scores that satisfy z<2.0 is 0.0228

• The proportion of scores that satisfy z<-1.0 is 0.1587

What is the standardized score (z-score) for a student who scored 500 on the old SAT scale?

• -30

• -0.13

• 0.13

• 0.27

Items produced by a manufacturing process are supposed to weigh 90 grams.  The manufacturing process is such, however, that there is variability in the items produced and they do not all weigh exactly 90 grams.  The distribution of weights can be approximated by a Normal distribution with mean 90 grams and a standard deviation of 1 gram.  About what percentage of the items will either weigh less than 87 grams or more than 93 grams?

• 0.15%

• 0.3%

• 6%

• 99.7%