Textbook Authors Must Be Careful That the Reading Level of Their

question 1

Essay

Textbook authors must be careful that the reading level of their book is appropriate for the target audience. Some methods of
assessing reading level require estimating the average word length. We've randomly chosen 20 words from a randomly
selected page in Stats: Data and Models and counted the number of letters in each word:
5, 5, 2, 11, 1, 5, 3, 8, 5, 4, 7, 2, 9, 4, 8, 10, 4, 5, 6, 6
-For a more definitive evaluation of reading level the editor wants to estimate the text's
mean word length to within 0.5 letters with 98% confidence. How many randomly selected
words does she need to use?

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Definitions:

Binomial Distribution

A probability distribution that describes the number of successes in a fixed number of independent trials, each with the same probability of success.

Poisson Distribution

A probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time or space, assuming these events occur with a constant mean rate and independently of the time since the last event.

Hypergeometric Probability

The probability of a certain number of successes in draws from a finite population without replacement, where each draw can result in a success or a failure.

Continuous Probability

The probability of outcomes in a continuous range of values rather than discrete outcomes.