5-520

Assignment 5

PH520

1. Based on the data from CDC, we assume the distribution of height for a one-year-old boy follows a normal distribution with mean 87.25 cm and standard deviation 3.52 cm.

(Hint: find the z score based on the probability, then do the backward transform to find matching height)

1) Find the top 10% of one year old boy ‘s height should be above ___________cm.

2) Find the lower 5% of one year old boy’s height should be below ______cm

2. You are reviewing a publication, and the authors state in a statistic in the results section. It has a large p-value (p < 0.20). The discussion section states that, even though the p-value indicates that the null parameter cannot be rejected, the research hypothesis may still be true because the study had low power.

Question 1: Why does low power cause the authors to contradict the conclusion provided by the
p value?

Question 2: Interpret the p value.