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May 4, 2016

# Homework Help: Probability and statistics

Posted by Arun on Friday, March 2, 2012 at 3:23am.

5. The probabilities that the lifetime of a randomly chosen device is below average, average, above average are respectively 0.2, 0.5, and 0.3. The probability that the 3 randomly chosen devices lifetimes of 2 are above average and 1 below average equals

a. 0.054
b. 0.018
c. 0.036
d. 0.012
• Probability and statistics - Writeacher, Friday, March 2, 2012 at 7:54am

If all you do is post your entire assignment, with no evidence of thinking on your part, nothing will happen since no one here will do your work for you.

But if you are specific about what you don't understand about the assignment or exactly what help you need, someone might be able to assist you. Ask specific questions!

• Probability and statistics - Anonymous, Tuesday, March 13, 2012 at 1:39pm

.054

• Probability and statistics - Anonymous, Tuesday, May 29, 2012 at 5:26pm

Question 1 of 1:
Finding Standard Deviation
A simple random sample of FICO credit rating scores is listed below:

714 751 664 789 818 779 698 836 753 834 693 802
Find range, variance, and standard deviation.
As of this writing, the mean FICO score was reported to be 678. Based on these results, is a FICO score of 500 unusual? Why or why not?