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Chapter 2: Q T2.8. (page 149)

The distribution of the time it takes for different people to solve a certain crossword puzzle is strongly skewed to the right with a mean of 30 minutes and a standard deviation of 15 minutes. The distribution of z-scores for those times is

a. Normally distributed with mean 30 and SD 15

b. skewed to the right with a mean 30 and SD 15

c. Normally distributed with mean 0 and SD 1

d. skewed to the right with mean 0 and SD 1

e. skewed to the right, but the mean and standard deviation cannot be determined without more information.

Short Answer

Expert verified

The correct option is (d) skewed to the right with mean 0 and SD 1

Step by step solution

01

Given information

With a mean of 30 minutes and a standard deviation of 15 minutes, the distribution of how long it takes different people to complete a crossword puzzle is highly skewed to the right.

02

Explanation

With a mean of 30 minutes and a standard deviation of 15 minutes, the population distribution would be biased to the right. The shape of the z-score distribution is always the same as the shape of the population distribution, indicating that the z-scores have a right-skewed distribution.

However, because z-scores are the standardized form of data values, they always have a mean of zero and a standard deviation of one.

Hence, the correct option is (d)

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