Evolutionary theories often emphasize that humans have adapted to their physical environment. One such theory hypothesizes that
people should spontaneously follow a 24-hour cycle of sleeping and wakingdash–even if they are not exposed to the usual pattern of sunlight. To test this notion, eight paid volunteers were placed (individually) in a room in which there was no light from the outside and no clocks or other indications of time. After a month in the room, each individual tended to develop a steady cycle. Their cycles at the end of the study were 2424, 2828, 2424, 2222, 2525, 2626, 2626, and 2525 . Using the 0.05 level of significance, what should be concluded about the theory that 24 hours is the natural cycle
Given that evolution theory hypothesizes that people should spontaneously follow a 24-hour cycle of sleeping and wakingdash–even if they are not exposed to the usual pattern of sunlight.
Sample size n = 8
df = 8- 1=7
Since population std deviation is not known, and sample size is small we can use only t test
(two tailed test at 5% level of significance)
24
28
24
22
25
26
26
25
mean 25
sd 3.142857143
se 1.111167799
Test statistic = Mean diff/se = 1.595
p = 0.1546
since p >0.05, accept null hypothesis.
There is no evidence to prove that the steady cycle is different from 24 hours.
