The lengths of lumber a machine cuts are normally distributed with a mean of 105 inches and a standard deviation of 0.7 inch ?
(a) What is the probability that a randomly selected board cut by the machine has a length greater than 105.21 inches?
b) A sample of 38 boards is randomly selectedWhat is the probability that their mean length is greater than 105.21 Inches?
(A) Probability is-
(B) Probability is-
- rotchmLv 74 weeks ago
Hints: a) Convert 105.21 to z space via z=(x-avg)/std. Then lookup in your z table.
b) For a sample of n, the avg remains the same. The sd becomes [left for you].
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