Question

Mr. Carroll surveyed 8 band members to see how many hours they practiced during one week. The results are shown below.2 4 4 5 5 6 6 81) what is the mean number of hours spent practicing by this sample of band students?2) What is the deviation for the person who spent 2 hours practicing?3) What is the standard deviation? (round two decimals)Blank # 1Blank # 2Blank # 3

Answer 1

The mean number is the total hours expended divided by

the number of members

then first we sum up all the hours of practice

2+4+4+5+5+6+6+8= 40 hours

now we divide the result by the number of members 40/8 = 5

so then the mean number of hours practicing is 5 hours

2) for the second part

the deviation is the difference between the mean number and the number by person.

So in this case the difference is 5 - 2 = 3 .

Then the deviation is 3 hours

3) for the 3rd question

standard deviation is the dispersion of the data numbers

is calculated by a square root formula

First we calculate the deviation of each band member

(5-2),(5-4),(5-4),(5-5),(5-5),(5-6),(5-6)

then each result is squared to obtain

9, 1,1,0,0,1,1 . Now we sum up this results

9+1+1+0+0+1+1= 13

Now divide this result by number of band members minus 1

so it is 13/(8-1) = 13/7

Finally calculate the square root of 13/7

It gives 1.36