Saturday

September 20, 2014

September 20, 2014

Posted by **GetYourLeash** on Friday, July 22, 2005 at 1:24am.

You need to change the times to Z-scores — scores given in terms of standard deviations.

Z = (X - µ)/SD, where X is the particular value, µ = the mean and SD is the standard deviation.

Once the Z scores are obtained, look it up in a table in the back of your statistics textbook called something like "areas under the normal distribution." Find the proportions between those Z-scores and the mean for both values and add them together to get the probability that the life of the bulb will be between these two values.

Although I did not solve the problem completely for you, I did tell you the process for reaching a solution. This will mean that you will have to exert a little more effort, time and thinking, but I hope it will help you to learn more.

I hope this helps. Thanks for asking.

huh

**Answer this Question**

**Related Questions**

math - 1) A light bulb producing company states that its lights will last an ...

Management - The bulbs manufactured by a company gave a mean life of 3000 hours ...

statistics - A new extended-life light bulb has an average service life of 750 ...

Statistics - The life of an electric light bulb is known to be normally ...

Probability and Statistics - For questions 1- 5 use confidence intervals to ...

statitics - a light bulb manufacture gaurentees that the mean life of a certain ...

probability and statistics - An electrical firm manufactures light bulbs that ...

Statistics - An electrical firm which manufactures a certain type of bulb wants ...

Stats - A new extended-life light bulb has an average service life of 750 hours...

Math - A consumer buys n light bulbs, each of which has a lifetime that has a ...