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August 29, 2015
Posted by **pallavi** on Thursday, March 15, 2012 at 11:58am.

31 42 50 25 29

40 36 24 29 30

40 46 38 34 26

24 22 39 40 21

In this question, i had to use stem and leaf method..and using box and whiskers.

For median, i got10.5 which is 32.5

lower quartile, i got23.5 and upper quartile, i got 15 +16/2 which is 40..

for mean which is EFM/EF which is 668/20 = 33.4

(the answers are correct..and has

already been corrected)

In this question, u have to draw the distribtution table..

MY problem is how you calculate the standard deviation????

PS: I know its formula..but i dnt get the right answer which is supposed to be 8.33

I would be very grateful if somework can help me in that part...in details????

- STATISTIC(STANDARD DEVIATION, PLS HELP) -
**Steve**, Thursday, March 15, 2012 at 2:35pmmean = 33.3

differences:

-2.3,8.7,16.7,-8.3,-4.3,6.7,2.7,-9.3,-4.3,-3.3,6.7,12.7,4.7,0.7,-7.3,-9.3,-11.3,5.7,6.7,-12.3

squares:

5.29,75.69,278.89,68.89,18.49,44.89,7.29,86.49,18.49,10.89,44.89,161.29,22.09,0.49,53.29,86.49,127.69,32.49,44.89,151.29

sum of squares: 1340.2

divide by n-1: 70.54 <-- variance

take root: 8.40

Done it by hand, and several online calculators. Can't get 8.33