Question 14.46

14.46 Time levels of scale.

Recall Exercise 7.62 (page 396). This experiment actually involved three groups. The last group was told the construction project would last 12 months. Here is a summary of the interval lengths (in days) between the earliest and latest completion dates.

timescl

Group
1: 52 weeks 30 84.1 55.7
2: 12 months 30 104.6 70.1
3: 1 year 30 139.6 73.1
  1. Is this an observational study or an experiment? Explain your answer.
  2. Use graphical methods to describe the three populations.
  3. Examine the conditions necessary for ANOVA. Summarize your findings.