# Math

The batteries from a certain manufacturer have a mean lifetime of
890
hours, with a standard deviation of
90
hours. Assuming that the lifetimes are normally distributed, complete the following statements.

1. 👍 0
2. 👎 0
3. 👁 257
1. What statements? You cannot copy and paste here.

Just guessing:

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/probabilities related to your Z scores.

1. 👍 0
2. 👎 0
posted by PsyDAG

## Similar Questions

1. ### Statistics (Math 210)

Hi there, I am doing my statistics homework and am having trouble with a few problems. I sincerely appreciate any help I receive! :) A manufacturer claims that the mean lifetime of its lithium batteries if 1200 hours. A homeowner

asked by Chris on December 4, 2016
2. ### statistics

A manufacturer claims that the mean lifetime of its lithium batteries is 1400 hours. A homeowner selects 25 of these batteries and finds the mean lifetime to be 1380 hours with a standard deviation of 80 hours. Test the

asked by S on December 5, 2015
3. ### statistics

A company produces batteries whose lifetimes are normally distributed with a mean of 100 hours. It is known that 90% of the batteries last at least 40 hours. (i). Estimate the standard deviation lifetime. (3 marks) (ii). What

asked by Ravi on April 26, 2013
4. ### Statistics

A battery manufacturer is positive that its AA batteries last for 1,000 hours. However, you’re working for Consumer Reports and you don’t agree with what they say about their product. So, you buy 400 batteries and you test

asked by Mike on November 22, 2011
5. ### Stats

The lifetime of a particular type of battery is normally distributed with a mean of 1100 days and a standard deviation of 80 days. The manufacturer randomly selects 400 batteries of this type and ships them to a departmental

asked by Dherain on June 5, 2008
1. ### statistics

The lifetime of a 2-volt non-rechargeable battery in constant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than

asked by Anonymous on May 31, 2013
2. ### Statistics

The lifetime of a 2-volt non-rechargeable battery in contant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than ?

asked by Karen on September 2, 2009
3. ### Statistics

The lifetime of a 2-volt non-rechargeable battery in contant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than ?

asked by Karen on September 2, 2009
4. ### Statistics

The lifetime of a certain smart phone battery has an unknown distribution with mean value of 8 hours and standard deviation of 2 hours. What is the approximate probability that the average battery lifetime of a sample of 36

asked by jacob on December 12, 2011
5. ### Statistics

The lifetime of a certain smart phone battery has an unknown distribution with mean value of 8 hours and standard deviation of 2 hours. What is the approximate probability that the average battery lifetime of a sample of 36

asked by jacob on December 12, 2011

More Similar Questions