. Find the Sample Standard Deviation for Brand A

Find the sample standard deviation for Brand A, listed in Example 3.9.

Recall the sample mean for Brand A: = _____

Brand A

10

60

50

30

40

20

Solution, by hand:

or, using the shortcut formula that does not use the mean of the sample,

Solution, using the TI84 calculator:

Enter the six data values into one list.

1:EditSelect list and enter data.

-> CALC1: OneVarStats

* Enter screen of entry

* Enter screen of results

Now find the standard deviation of Brand B.___________________

What does this indicate about the variation of the two brands?

The sample standard deviation is Sx.

If a population is entered, the population standard deviation is sx.