# statistic (2)

• Aug 21st 2009, 06:03 AM
thereddevils
statistic (2)
The number of personal computers sold in a week by a computer for a period of 25 weeks is given as follows .

10 8 7 4 4 18 9 14 17 11 5 4 5 7 10 12 14 10 9 29 7 6 5 20 15

Find the percentage of the weeks that the weekly sales of the personal computers are within one standard deviation from the mean .

I don understand what the questino is asking .THanks for the help .
• Aug 21st 2009, 02:32 PM
mr fantastic
Quote:

Originally Posted by thereddevils
The number of personal computers sold in a week by a computer for a period of 25 weeks is given as follows .

10 8 7 4 4 18 9 14 17 11 5 4 5 7 10 12 14 10 9 29 7 6 5 20 15

Find the percentage of the weeks that the weekly sales of the personal computers are within one standard deviation from the mean .

I don understand what the questino is asking .THanks for the help .

Calculate the mean of the data. Calculate the standard deviation of the data. Calculate the interval [mean - sd, mean + sd]. Count how many data lie in this interval. Convert the number you counted into a percentage out of 25.
• Aug 22nd 2009, 06:38 AM
thereddevils
Quote:

Originally Posted by mr fantastic
Calculate the mean of the data. Calculate the standard deviation of the data. Calculate the interval [mean - sd, mean + sd]. Count how many data lie in this interval. Convert the number you counted into a percentage out of 25.

understood , thanks a lot .