I really need help on this question - worth alot of points on my HW

What are the mean and standard deviation of the difference between the Test A score and the Test B score (Test B - Test A)?
Mean = 4.83785 (which is right) Standard deviation = HELP PLEASE!

In excel is gave us:

Test A:

41.25006451
63.26492946
65.27934654
65.09548082
63.09355792
76.81460426
72.0103463
76.74769956
80.56626991
67.71717887
61.26185833
81.87666988
55.59661583
71.58822707
75.08449523
56.47732503
77.07568609
70.72571914
64.53790372
73.57915644
75.82466476
68.22181201
52.94825821
69.30783963
83.82892299
54.81963451
80.63175353
72.93635969
62.99382046
81.4234914
67.13075943
87.76235115
65.78660584
85.17988642
60.16055119
71.6733103
84.33467026
74.52113148
79.39377208
81.49088496
80.36038305
78.06800165
60.42250841
75.82896212
75.94533197
61.48436621
74.60835202
79.6734417
59.45059963
73.20286438
45.05215846

Test B:

38.89985575
72.41068371
69.19120661
66.79448571
65.07013833
82.19231514
82.07686843
82.70594318
85.96249355
74.09330689
70.24446287
91.49693479
61.14388494
75.06481548
78.17124807
59.28890683
81.14493536
76.02513275
69.11248871
78.75194793
81.14530598
71.81604243
54.88799726
75.34101425
87.27409632
58.15615278
89.45134478
75.78104825
68.71099568
84.94637196
72.65657242
94.51570914
71.04360858
91.4199688
71.36659743
74.38730446
89.22000912
79.03860929
86.55711209
86.90934575
84.46544708
80.6963828
65.70278511
79.56534315
80.71434532
66.31548327
81.50924256
80.87440957
60.37583372
81.28443479
44.87221324

Any help for the answer to the S.D. would be greatly appreciated

thanks in advance

3/17/2006 1:52:18 PM

and i tried =STDEV(A2:A52) and =STDEV(B2:B52)

and i subtracted b from a and it didnt work :/

51 total numbers for each btw

3/17/2006 1:53:24 PM

mean is 4.837894071

standard dev. is 2.614973704

i think at least...but i did it quick so could be off

3/17/2006 3:37:52 PM

tyvm

3/17/2006 3:45:03 PM

was that right?

3/17/2006 3:45:40 PM

would you know the test Statistic by any chance?

3/17/2006 3:55:16 PM

yea it was right

i figured out how to do it too, but now the test stat wont work

screw this class

3/17/2006 3:55:38 PM

sorry man, dont have time to crunch the numbers, and i havnt seen the whole problem....plus i havnt taken the course in few years....this link should help though...if im on when i get home ill take a look if you want....you should be able to figure it out using the link though

http://ccnmtl.columbia.edu/projects/qmss/t_one.html

3/17/2006 5:06:48 PM