The life of a tire is normally distributed with a mean of 30,000 miles. The standard deviation is 2000 miles.

1. What is the probability that a tire last more than 28,000 miles?

0.8413

The probability that a tire last more than 28,000 miles is 0.8413

2. Use your answer from #1. If a company purchased 2000 tires, how many would the company expect to last more than 28,000 miles?

1683

The company expect to last more than 28,000 miles are 1683

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Q 2.

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

3. What percent of the product lasts less than 6 days?

2.275 %

The percent of the product lasts less than 6 days is 2.275 %

need help with the following:

4. What percent of the product lasts 15 or more days?

In an Oreo factory, the mean mass of a cookie is 4 g. For quality control, the standard deviation is 0.2 grams.

5. If 10,000 cookies are produced, how many cookies are within 0.15 g of the mean?

6. Cookies are rejected if they weigh more than 4.5 g or less than 3.9 g. How many cookies would you expect to be rejected in a sample of 20,000 cookies?

The fuel efficiency of cars currently registered in Indiana is 24 miles per gallon with a standard deviation of 5.5 mpg.

7. What percent of all cars get less than 15 mpg?

8. What percent of all cars get between 20 and 30 mpg?