1.When robin eggs are weighed, it turns out that the weights have a normal distribution with a mean of 17.5 mg and a standard deviation of 3.5 mg. Use the 68-95-99.7 rule to answer the following.

Answer

a)What percent of robin eggs have a weight that is between 10.5 mg and 17.5 mg?

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b)What percent of robin eggs have a weight that is between 7 mg and 10.5 mg?

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c)What percent of robin eggs have a weight that is more than 28 mg?

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d)What percent of robin eggs have a weight that is between 21 mg and 28 mg?

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e)What percent of robin eggs have a weight that is between 14 mg and 21 mg?

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2.A forest product company claims that the amount of usable lumber in harvested trees averages 172 cubic feet and has a standard deviation of 12.4 cubic feet. Assume the distribution have a normal distribution.Use the 68-95-99.7 rule to answer the following.

Answers

a)When trees are harvested, what percent of trees contain more than 159.6 cubic feet of usable lumber?

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b)When trees are harvested, what percent of trees contain less than 172 cubic feet of usable lumber?

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c)Of 2000 harvested trees, how many do we expect to have between 147.2 and 196.8 cubic feet of usable lumber?

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d)When trees are harvested, what percent of trees contain less than 209.2 cubic feet of usable lumber?

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e)Of 2000 harvested trees, how many do we expect to have between 134.8 and 184.4 cubic feet of usable lumber?

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