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04-24-2006, 04:42 PM
A salt company packages salt in 5-pound bags. The amount of salt per bag varies according to a normal distribution which has a mean of 5 lbs and a standard deviation of 0.05 lbs. A sample of 25 bags is selected from the day's production and the mean of the sample is determined. If it is less than 4.98 pounds, the fill per bag will be increased.

What is the probability that this will happen? Draw a graph of the normail distribution and indicate the area of interest.

royhaas
04-25-2006, 07:33 AM
Start by calculating the z-score.

04-25-2006, 01:15 PM
do you use 5 to determine z-score or 4.98?

tkhunny
04-25-2006, 01:50 PM
Yes. Also, used 0.05 and sqrt(25).

Do you have a book?

04-25-2006, 04:38 PM
yes

tkhunny
04-25-2006, 05:00 PM
So, will you share with us what you get for the z-score of the mean of a sample?

04-26-2006, 03:07 PM
do you get the z-score by looking on that chart in the book? and can you tell me how to get the z-score?