Texas Instruments TI-60 - Page 37

CHAPTER 1-4
STATISTICS
2 Enle» a on*- or two-digit number indicating the number ot times you
want to enter the data point This number must be an integer value,
regardless ot the current number-system setting
3. Press If*!
You can us* ;ind [Frq] to remove multiple data points, instead of adding
them, by pressing INV] 03! instead ot 31
You can us* the '»J key In conjunction with the [£U key to enteer data
points with both x and y values as follows:
1. Enter an x value and press [jijxjD
2 Enter a y value and press 31
Repost the procedure to enter additional data points
You can also follow this procedure with the IfiVD USD key sequence to
remove data points, and with the ;2mf I [Frq] key sequence to enter or
remove multiple data points.
2nd (Mean) 2nd [Mean] x«yj — Mean Keys
The 2nd [Mean] key gives the mean ot the y values entered Then
pressing x'-y gives the mean of the "x" values entered Note that the
2nd [Mean] key removes any pending operations
2nd [<m-1|, 2nd (on). 2nd [on-l] «*»y 2nd [on] sub¬
standard Deviation Keys
The 2nd [otvl] and 2nd [<m] keys give the sample and populalion
standard deviation of the y data points lhal have been entered The 2nd
[,.n-l] x-.y an d 2nd [ m] x-.y keys give Ihe sample and population
standard deviation of the x data points that have been entered
The ditterence between the sample standard deviation < 2nd fen-1] and
2nd (on-1) x-.y ) and the population standard deviation < 2nd [on]
and : 2nd [on] [«**_» ) becomes very small for over 30 data points A
population is usually a large set ot Items, and a sample is a smaller portion
selected Irom the population Note that the 2nd [<m-1], 2nd [on].
2nd [<m-1| x-.y .and 2nd [on] x-y keys remove any pending
operations
Example :
A class of twelve students made the following scores on a math test
Calculate the mean and the standard deviation
96 81 85 76 86 57 98 75 78 100 72 70
Because you are entering all of the scores. Pe sure to use the "n weighted"
standard deviation
27-GB