Posted by **Sara** on Monday, July 1, 2013 at 7:01pm.

A company has developed a new type of light bulb, and wants to estimate its mean lifetime. A simple random sample of 12 bulbs had a sample mean lifetime of 692 hours with a sample standard deviation of 30 hours. It is reasonable to believe that the population is approximately normal. Find the lower bound of the 95% confidence interval for the population mean lifetime of all bulbs manufactured by this new process.

Round to the nearest integer. Write only a number as your answer. Do not write any units.

## Answer this Question

## Related Questions

- Statistics - Can anyone tell me how to use TI-84 calculator to solve this ...
- statistics - Solve the problem. The lifetime of a new brand of light bulb can be...
- statistics - The mean lifetime of a sample of 100 light tubes is 1570 hours ...
- statitics - a light bulb manufacture gaurentees that the mean life of a certain ...
- statistics - 2. The new Twinkle bulb has a standard deviation hours. A random ...
- statistics - the life of light bulbs is distributed normally. The variance of ...
- Math - A consumer buys n light bulbs, each of which has a lifetime that has a ...
- Math - A consumer buys n light bulbs, each of which has a lifetime that has a ...
- Statistics - An electrical firm which manufactures a certain type of bulb wants ...
- Stats - The distribution of lifetimes for a particular brand of lightbulbs has ...