Portfolio

Numerical Summaries and Boxplots

 

Data:  Survey of Study Habits and Attitudes—data from IPS 5/e Exercise 7.84, p. 513.

 

Women's scores

154

109

137

115

152

140

154

178

101

103

126

126

137

165

165

129

200

148

 

Men's scores

108

140

114

91

180

115

126

92

169

146

109

132

75

88

113

151

70

115

187

104

 

TI-83 Plus numerical summaries

 

Enter the women's scores into list L1. (Use STAT 1:Edit.)

Enter the men's scores into list L2.

 

You can get the mean, standard deviation, and five-number summary all at once for the women's scores as follows.

STAT

 

Right cursor

CALC

1

1-Var Stats

2nd [L1]

 

ENTER

 

Scroll down to see all the output.

 

 

Follow the same procedure for list L2 to get the numerical summaries of the men's scores.

 

Record here the mean, standard deviation, and five-number summary for both data sets. 

(Give answers to one decimal place.)

 


 

Boxplot and side-by-side boxplots

 

Click on WINDOW;

set Xmin to a value less than the minimum value in your data set,

and set Xmax to a value greater than the maximum value in your data set.

The TI-83 Plus will draw the boxplot horizontally rather than vertically as in our text.

 

2nd [STAT PLOT]

Turn on Plot1 and turn off the others if necessary if you are making one boxplot.

Turn on Plot1 and Plot2 if you are making two side-by-side boxplots.

For each plot, change Type to the fourth or fifth type.

The fourth type is a modified boxplot, showing outliers.

The fifth type is an ordinary boxplot.

For Plot1, set Xlist to L1. For Plot2, set Xlist to L2.

GRAPH                                  displays the boxplots.

TRACE                                   Use the arrow keys to see the numbers associated with each boxplot component.

 

Draw side-by-side boxplots for the women’s and men’s SSHA scores.

Use ruled paper or a ruler to make the scale on the score axis accurate.

Also describe in words how the distributions compare.