MTH130 - Zelazo et al. (1972) investigated the variability

MTH130 Final Exam Problems

1. 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.

Conduct an eight step Hypothesis test to determine if there is a statistically significant difference between the four group.

2. The San Diego Metro transit authority (known as MTA) is expanding services from San Diego to Escondido. There are four possible alternative routes (1) via US 15, (2) via US 8, (3) via US 5, and (4) via US 123. MTA conducted several tests to determine whether there was a difference in the mean travel time along the four routes. Because there will be many different drivers, the test was set up so each driver drove around each of the four routes. Below is the travel time, in minutes, for each driver – route combination.

At the .05 significance level, is there a difference in the mean travel time along the four routes? Are there significant difference between the drivers? If we remove the effects of the drivers, is there a difference in the mean travel time? Conduct an eight step hypothesis testing, and ensure that each of the elements of the eight steps have the appropriate responses. Don’t forget to answer the objective questions stated about.