Many Americans Complain About Being Sleep Deprived

Multiple Choice

Many Americans complain about being sleep deprived. A team of psychologists researched the reasons for this sleep deprivation. After determining that one reason was poor time management, they devised a program to help people manage their time better. They recruited a random sample of 30 people at a major shopping center and randomly split them into three groups of size 10. Group 1 (the controls) received a logbook asking them to record the number of hours slept for a week but nothing else. Group 2 (the informed group) was shown a video to help improve time management. Group 3 (the intervention) participated in a two-day training course on improving time management. Groups 2 and 3 were also asked to keep records for one week on the number of hours slept. The psychologists were interested in learning if providing information or an intervention affects sleep time. The F-value derived from their data is F = 3.67. Therefore, we can conclude that:

A) all means are the same, since P-value > 0.10.
B) all means are different, since P-value > 0.10.
C) we do not have enough information, since we are not given the P-value.
D) the P-value is > 0.10, so there is no evidence against the null hypothesis that all means are equal.