SOLUTION: Alight I kinda get the gist of what is going on with this problem but i'm having a hard time with the mean deviation which would mean I will have a hard time with the variance and

Algebra ->  Probability-and-statistics -> SOLUTION: Alight I kinda get the gist of what is going on with this problem but i'm having a hard time with the mean deviation which would mean I will have a hard time with the variance and       Log On


   

Question 84218This question is from textbook elementary statistics in social research
: Alight I kinda get the gist of what is going on with this problem but i'm having a hard time with the mean deviation which would mean I will have a hard time with the variance and standard deviation.
A focus group of 10 adults was chosen to evaluate the performance of a candidate during a presidential debate. Each member of the group rated the overall perfomance on a scale of 1 (poor) to 10 (superior). The ratings given the canidate were as follows:
4 5 8 7 9 8 7 3 6 7
Range 9-3=6 so the range is 6.
Mean deviation
I am not sure how to do this part at all...or the variance and standard devation part. please can you help. This question is from textbook elementary statistics in social research

Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
Alight I kinda get the gist of what is going on with this problem but i'm having a hard time with the mean deviation which would mean I will have a hard time with the variance and standard deviation.
A focus group of 10 adults was chosen to evaluate the performance of a candidate during a presidential debate. Each member of the group rated the overall perfomance on a scale of 1 (poor) to 10 (superior). The ratings given the canidate were as follows:
4 5 8 7 9 8 7 3 6 7
Range 9-3=6 so the range is 6.
Mean deviation
I am not sure how to do this part at all...or the variance and standard devation part. please can you help.
TABULATE AND DO AS FOLLOWS.HOPE IT IS CLEAR.PLEASE COME BACK IF IN DOUBT
x X=x-M X^2
1 4 -2.4 5.76
2 5 -1.4 1.96
3 8 1.6 2.56
4 7 0.6 0.36
5 9 2.6 6.76
6 8 1.6 2.56
7 7 0.6 0.36
8 3 -3.4 11.56
9 6 -0.4 0.16
10 7 0.6 0.36

SUM=S= 64 S.S.D. = 32.4 S.S.D=SUM OF SQUARES OF DEVIATIONS
N0.=N = 10 N0. = N = 10
MEAN=M= 6.4 VARIANCE=V= 3.24 =MEAN OF SUM OF SQUARES OF DEVIATIONS
S.D = SQRT.(V) 1.8 =ROOT OF MEAN OF SUM OF SQUARES OF DEVIATIONS