# math-statistics

posted by .

A manufacturer claims that the life span of its tires is 50,000 miles. You work for a consumer protection agency and you are testing this manufacturer's tires. Assume the life spans of the tires are normally distributed. You select 100 tires at random and test them. THe mean life span is 49,271 miles. Assume รณ = 800 miles. Assuming the manufacturer's claim is correct, what is the probability the mean of the sample is 49,271 miles or less.

- I used the central limit theorem to answer the question..I'm not sure of my answer. I just wanted to check it with somebody else's answer to make sure I did it right ...Thank you for taking time to read this.

• math-statistics -

• math -

m>n

40

20

• math -

huh?

## Similar Questions

1. ### Statistics

A purchasing agent for a trucking company is shopping for replacement tires for their trucks from two suppliers. The suppliers' prices are the same. However, Supplier A's tires have an average life of 60,000 miles with a standard deviation …
2. ### Statistics

A purchasing agent for a trucking company is shopping for replacement tires for their trucks from two suppliers. The suppliers' prices are the same. However, Supplier A's tires have an average life of 60,000 miles with a standard deviation …
3. ### Prob and Stat

A tire manufacturer guarantess that its tires will last for at least 60,000 miles. If the tire fails earlier, the manufacturer offers a prorated replacement. Too many such replacements are bad for business, so the manufacturer tests …
4. ### math

a tire manufacturer believes that the tread life of its tires are normally distributed and will lst an average of 60,000 miles with a standard deviation of 3,000 miles. sixty-four randomly selected tires were tested and the average …
5. ### stats

The life of tires manufactured by Omega Tires Inc is believed to be normally distributed with a mean of 110,000 km and a standard deviation of 5,000 km. A random sample of 200 tires is tested . What is the problability of the mean …
6. ### Statistics

The life spans of three randomly selected tires are 31,950 miles, 36,050 miles, 34,000 miles. Using the empirical rule, find the percentile that corresponds to each life span.
7. ### statistics

the life spans of three randomly selected tires are 31,400 miles, 40,600 miles and 36,000 miles. Using the empirical rule, find the percentile that corresponds to each life span.
8. ### Statistics

Problem: you work for a manufacturer of tires (average life of your tires is 60.000 km with a standard deviation of 8.000 km). A supplier offers you new material that he says will increase by 10% the mileage of the tires you produce. …
9. ### statistics

The tread life a certain brand of tires is known to be normally distributed with a mean of 60,000 miles and a standard deviation of 5,000 miles. The company wishes to set the warranty so that only 4% of the tires will need to be replaced. …
10. ### statistics

The tread life a certain brand of tires is known to be normally distributed with a mean of 60,000 miles and a standard deviation of 5,000 miles. The company wishes to set the warranty so that only 4% of the tires will need to be replaced. …

More Similar Questions