Posted by **jericho** on Tuesday, October 2, 2012 at 7:28am.

a manufacturer of bicycle tire has developed a new system which he claims an average life span of 5 years. with the standard deviation of 1.2 years a dealer product claims that the average life span of 150 samples is only 3.5 years. test the difference of population and sample means at 5% level of significance. what is the answer?

- statistics -
**PsyDAG**, Tuesday, October 2, 2012 at 1:21pm
Do you really mean samples? If so, what is the n for each sample? If you really mean n, use information below.

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

## Answer This Question

## Related Questions

- math - The life span of a DVD player produced by one major company is known to ...
- Statistics/Probability - The life span of a calculator has a normal distribution...
- math-statistics - A manufacturer claims that the life span of its tires is 50,...
- Statistics - A manufacturer has observed that a certain product tends to fail ...
- statistics - A store manager claims that the average age of his customers is ...
- statistics - A store manager claims that the average age of his customers is ...
- Statistics (Math 210) - Hi there, I am doing my statistics homework and am ...
- Standard Error Of Mean? - In a random sample of 30 tires of the same type, it is...
- Statistics - An automobile in surer has found that repair claims have a mean of...
- Statistics - A purchasing agent for a trucking company is shopping for ...

More Related Questions