Answer to Question #300575 in Statistics and Probability for Kulot

Question

Zelazo et al. (1972) investigated the variability in age at first walking in infants.

Study infants were grouped into four groups, according to reinforcement of

walking and placement: (1) active (2) passive (3) no exercise; and (4) 8-week

control. Sample sizes were 6 per group, for a total of n=24. For each infant,

study data included group assignment and age at first walking, in months.

The following are the data and consist of recorded values of age

(months) by group:

Active

Group

Passive

Group

No-Exercise

Group

8-Week

Control

9.00

11.00

11.50

13.25

9.50

10.00

12.00

11.50

9.75

10.00

9.00

12.00

10.00

11.75

11.50

13.50

13.00

10.50

13.25

11.50

9.50

15.00

13.00

12.35