Pulse for Teenagers (12-19) versus Adults (20 and up):

Stem-and-Leaf Plots

12-19 N = 28

Leaf Unit = 1.0

2 4 01

2 4

5 5 002

8 5 588

10 6 01

12 6 88

(5) 7 00224

11 7 66899

6 8 00

4 8

4 9 3

3 9 78

1 10 2

20-70 N = 29

Leaf Unit = 1.0

4 4 0003

5 4 6

9 5 2344

11 5 68

14 6 114

(1) 6 7

14 7 22

12 7 6666

8 8 03

6 8 8

5 9 344

2 9 88

The stem and leaf plots allow us to look at the different ranges and patterns in the data including outliers (points that do not appear to fit the rest of the data).

Descriptive Statistics : These statistics show the general tendency of the data.

Variable N Mean Median TrMean StDev SE Mean

12-19 28 69.89 71.00 69.81 16.28 3.08

20-70 29 67.76 67.00 67.67 18.44 3.43

Variable Minimum Maximum Q1 Q3

12-19 40.00 102.00 58.00 79.00

20-70 40.00 98.00 53.50 81.50

These histograms are a visual way of analyzing the data.

Two Sample T-Test an

These side by side boxplots allow us to compare the ranges of the data including minimums, maximums, 25^th and 75^th percentiles, and the medians.

Two sample T for 12-19 vs 20-70

N Mean StDev SE Mean

12-19 28 69.9 16.3 3.1

20-70 29 67.8 18.4 3.4

95% CI for mu 12-19 - mu 20-70: ( -7.1, 11.4)

T-Test mu 12-19 = mu 20-70 (vs <): T = 0.46 P = 0.68 DF = 54

We used the t-test to compare the data sets because we did not have the standard deviation of the population. The t-test tells us that when we compare the probability value of .68 to .05 (the significance level), we retain the null hypothesis and conclude that are reasonably equal.