Three different brands of pain relief medication are availab

Three different brands of pain relief medication are available for minor aches and
pains. It is of interest to know whether the mean time to relieve the pain differs from
brand to brand. To find out, twelve individuals with minor aches and pains were
randomly assigned to one of the three brands. The time to relieve the pain (in
minutes) for each individual is provided in the table below.
Brand A    Brand B             Brand C
10              I5                      20
12               22                      25
15               25                      20
14               I9                       11

Given that the necessary assumptions are satisfied, can it be concluded. at the 2.5%
level of signiicance, that not all mean times to relieve pain are equal? Formulate
and test the appropriate hypotheses. Use the critical value approach.

Please show work - i am lost! thanks

Solution

H0: All means are equal

Ha: Not all are equal

Chi square test two tailed

The chi-square statistic is 5.2928. The P-Value is 0.506843. The result is not significant at p < 0.05.

Hence all means are equal.