# help!!!

as a part of her statistics coursework, Dan records her bus journey times to school on a random sample of 15 days. the times, in minutes are as follows

15.7 ,14.8 ,12.3, 18.6, 15.8, 13.4 ,14.7, 17.6 ,16.3

15.4 , 13.8 , 16.7 , 15.1 , 14.6, 12.6

A- use these data to estimate the mean and standard deviation of dan's bus journey time to school.

B- explain why dan did not somply record her bus journey times over a 3-week peroid.

Answers
To find the mean you add up all the numbers and then divide the answer by 15 because there are 15 numbers: (15.7+14.8+12.3+18.6+15.8+13.4+14.7+17.6+16.3+15.4+13.8+16.7+15.1+12.6)= 15.16
Julie H.
23 September 2012
To find the Standard deviation firstly you have to subtract the mean from each of your numbers then square each answer: (15.7-15.16)^2= 0.2916
Julie H.
23 September 2012
Do this for each of your numbers until you have 15 different answers. Finally add up all your different answers, divide the total by 15 and then square root your answer. That is the standard deviation.
Julie H.
23 September 2012
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