Homework Help: statistics

Posted by Sue on Saturday, March 2, 2013 at 2:43pm.

Boxes of bran flakes are known to be normally distributed with a mean weight of 475g and a standard deviation of 10g.Calculate the probability of a box having a weight exceeding 485 grams. Calculate the probability that the mean weight of sixteen boxes will exceed 480g.

statistics - MathGuru, Saturday, March 2, 2013 at 5:34pm
Use z-scores.

Formula for the first part:

z = (x - mean)/sd

With your data:

z = (485 - 475)/10

I'll let you finish the calculation.

Once you have the z-score, check a z-table for the probability. (Remember the problem is asking "weight exceeding" 485 grams.)

Formula for the second part:

z = (x - mean)/(sd/√n)

With your data:

z = (480 - 475)/(10/√16)

I'll let you finish the calculation.

Once you have the z-score, check a z-table for the probability. (Remember the problem is asking "mean weight... will exceed" 480 grams.)

I hope this helps and will get you started.

Answer this Question

Related Questions

Statistics - The amount of fill(weight of contents)put into a glass jar of ...
Statistics - I am so lost on this statistics question would someone help me ...
statistics - Assume the body weight of healthy fifth graders is normally ...
Statistics - Are these statements true or false? 1. The sample mean, the sample ...
statistics - The weights of steers in a herd are distributed normally. The ...
Statistics - The weights of the fish in a certain lake are normally distributed ...
Statistics - Assume there are two lakes containing trout and the weights of the ...
statistics - The most common intelligence quotient (IQ) scale is normally ...
statistics - The most common intelligence quotient (IQ) scale is normally ...
Statistics - . Suppose a certain species of fawns between 1 and 5 months old ...

For Further Reading

First Name:
School Subject:
Answer: