Wks 02, Chapters 3
_____________,_______________,_________
Surname(e.g. Straayer),
Given Name(e.g. Dave), class mtg. time
Begin with a subset of thumb data taken in a Statistics class, below.
Begin by filling in the Sum and Mean of the original data.
Data
65
55
63
65
67
68
61
63
58
56
Then fill in the deviation column. Each deviation is
<data value> - <mean>
Calculate the sum of these numbers and fill in. If it isn’t zero, it
should be very close.
Now, for each deviation, square it, and fill in the Deviation^2
column.
Add up and get a sum of the squared deviations. Record it in the
“Sum:” row.
Now, calculate the Mean of the squared deviations, in an odd way.
Instead of dividing by the count, n, divide by (n-1). There is a
reason for that, but for now, just take my word.
Deviation Deviation^2
Sum:
Mean:
Std. Dev
Finally, calculate the standard deviation by taking the square root of the “slightly different mean” of the squared
deviations, and fill that in.