Texas Instruments TI-83 Plus Software Manual page 88

_ Try-It!Ë on Your TI83 Plus
On Your Own
1. Enter the following math test scores in
Scores (L
1
99
96
92
88
84
78
74
70
66
64
2. Set up the histogram (
3. Graph the histogram using
correspond to these test scores: A = 100–90; B = 89–80; C = 79–70; D = 69–60; F = 59–0. Did
the graph display the way you expected? Why is it necessary to change the window values
manually?
4. Change the window values manually to group the data in intervals of 10. Remember that you
want the data grouped in intervals of 10 so you can see how many test scores fall into the
grade categories given above. You can tell the calculator to do this by setting
graphing window (
should be a little higher than the highest score to display a nice graph. Try setting the
window as
Xmin=50
5. Graph and trace the histogram again to see why these settings show the grades grouped by
scores that match the letter grades A, B, C, D, and F.
Hint: Remember that if you have functions defined and turned on in the Y= editor, the calculator graphs these at the same time as the
stat plot. To turn off a function, highlight the = sign next to it, and then press
You can also select FnOff to turn off all functions. To do this, press
Fundamental Topics in Science
(continued)
) Frequency (L
4
4
3
2
3
2
2
1
1
1
Ò
) where
Xlist=L
, and then trace (
ZoomStat
'
). Xmin should be a little less than the lowest score and
, ,
Xmax=100 Ymin= 4
© 2001 Texas Instruments
and .
L L
1 2
)
2
and in the
Freq=L
1 2
)
) the histogram. Letter grades
, , and
Ymax=15 Yscl=10
b
.
4:On/Off 2:FnOff.
•
TIp 7: Creating a Statistical Plot
menu.
STAT PLOTS
Xscl=10
Xmax
.
on the
_ _
TIp 7-4