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.