Monday

December 22, 2014

December 22, 2014

Posted by **Joy** on Sunday, January 22, 2012 at 5:38pm.

9.0 months 7.0 months

8.2 months 8.3 months

7.8 months 8.1 months

7.5 months 7.6 months

9.1 months 7.4 months

I calculated the standard deviation to be about 0.679.

Estimate the probability that a random chosen light will last as long as 7 months after installation. Assume the data to be described by a normal distribution.

Can anyone help me with the process I would use to calculate the answer? Thanks!

- science -
**PsyDAG**, Monday, January 23, 2012 at 11:39amI assume that you have calculated the mean to find the SD.

Z = (score-mean)/SD

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**

Statistics - Shown below are the data giving the length of life of lights in an ...

math - A person takes out a monthly installment loan of $2000 with an annual ...

Statistics - . A certain company makes 12-volt car batteries. After many years ...

Statistics - A certain company makes 12-volt car batteries. After many years of ...

math - John's account of 98.50 has been delinquent for 3 months. After 90 days ...

Financial Mathematics - The Z Corporation needs $180,000 in 60 months. If they ...

human growth and development - According to the Bayley Scales of Infant ...

stats - 2. The average age of a child in kindergarten is 66 months. The standard...

math - Mrs. Diaz wishes to save at least $1500 in 12 months. If she save $300 ...

stats - A manufacturer of automobile batteries claims that the distribution of ...