According to a study by the Centers for Disease Control, the national mean hospital stay after childbirth is 2.1 days. Reviewing records at her own hospital, a hospital administrator calculates that the mean hospital stay for a random sample of 81 women after childbirth is 2.3 days with a standard deviation of 1.2 days.
Test the claim that the mean hospital stay after childbirth for this hospital is significantly longer than the national mean of 2.1 days.
Is this a one-tailed or a two-tailed test?
A) one-tailed to the right
B) one-tailed to the left
C) two-tailed
A?
1 answer
You're right.
1 answer