A study of the
differences in cognitive
and patients diagnosed with schizophrenia was published
in the American Journal of Psychiatry (Apr. 2010).
The total time (in minutes) a subject spent on the Trail
Making Test (a standard psychological test) was used as
a measure of cognitive function. The researchers theorize
that the
will be larger than the corresponding mean
for normal subjects. The data for independent random
samples of 41 schizophrenics and 49 normal individuals
yielded the following results:
***PHOTO
Does the data provide significant evidence,
at the 4.6% level, that the population mean time for patients diagnosed with schizophrenia
exceeds the population mean time for normal individuals by more than 20 points?
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