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Lab Activity #5 Name(s)

Graphs :Histogram-Graphing Calculator Date _10/20/15_

Entering Data into the TI-83

To use the statistical functions built into the TI-83, we first have to enter data into lists. The TI-83 has six columns

(called lists L1, L2, L3, L4, L5, and L6) in which data can be entered.

Press the STAT key and then select 1:Edit. You will now the data screen with the six lists, L1 through L6 (use

your right arrow to see L4 through L6).

If there is already data in one of the lists, we need to clear the list. Do this by placing your cursor at the top of

the list you wish to clear and then hit the CLEAR button. DO NOT hit the DEL button; this will delete the list

from your calculator. Another way to clear a list is to press the STAT key and then select 4:ClrList using the

arrow keys, and then press ENTER. Then type in the list you want cleared (2ND key and 1 key for list L1) and

press ENTER.

Histograms: Are you as smart as a fifth-grader?

Before you start, look at the data in Table 1, does it tell you anything? Can you make a “story” about this big

list of numbers that gives the gist of the information it represents? Since data is the key to the universe, we

must be able to interpret it. Why not make a picture of it? Everyone understands pictures. The ability to transform

a mass of numbers into a picture could be one of the most valuable skills you ever learn.

In this activity you will use your TI graphing calculator to aid you in creating a histogram with different class

widths and analyze them.

Table 1: IQ scores for 60 randomly chosen fifth graders.

145 139 126 122 125 130 96 110 118 118

101 142 134 124 112 109 134 113 81 113

123 94 100 136 109 131 117 110 127 124

106 124 115 133 116 102 127 117 109 137

STAT 1350 Page 1

1. We need to enter the data into L1. (see Entering Data into the TI-83 at the end of this lab)

a. Let’s let the calculator help us find the min and the max by using STAT-SortA(L1)-Enter. Then

go back and look at your list and L1(1) = __81_ is now you MIN and L1(60) = __145_ is your

MAX.

2. To make a histogram with 3 classes we need all the data to fit in a class interval. Find CLASS WIDTH:

(MAX-MIN)/3 and choose the next highest integer (even if you get a whole number!) Set your window

so that:

XMIN=MIN-.5

XMAX=MAX+.5

XSCL=CLASS WIDTH

YMIN=0

YMAX=30

YSCL=1

3. The next step is to select histogram style for the plot. Press 2nd [STAT PLOT]. Highlight Plot1 and

press ENTER.

117 90 103 114 139 101 122 105 97 89

102 108 110 128 114 112 114 102 82 101

2

4. Then on the next screen highlight ON and hit ENTER then highlight the histogram shape, hit ENTER

In this example, we stored the data in L1, which should be the default of XList, if not, change Xlist to

L1 and FREQ = 1

5. Press GRAPH. Use TRACE to sketch your histogram here* (*Good graphs should have a title, both

axes should also have a title, both axes should have clearly marked scales!)

a. Which c l a s s

has the most number of students in it? 9th

3

Number of

students

y

IQ scores

x

IQ scores for Fifth Graders

b. What class has the student whose IQ is in the middle of the list? 11th

c. How would you describe the overall pattern of the data? random

d. How would you describe the distribution of the histogram? it’s spread from lowest to highest IQ

6. Change the number of classes to 15. Sketch you histogram here.

a. Which class has the most number of students in it? 7th

b. What class has the student whose IQ is in the middle of the list? 7th

c. How would you describe the overall pattern of the data? right-skewed

4

Number of

students

IQ scores

x

y

d. How would you describe the distribution of the histogram? it spread from 81 to 141

e. How does this histogram compare with the previous histogram? Which do you think is a better?

This histogram includes less IQ scores. The pervious histogram is better.

7. Let’s let the calculat

o r c h o o s e

t h e classes.

J u s t Z O O M

– ZOOMS

T A T . S k e t c h

here:

5

Number of

students

y

x

IQ