Professor Casey performs a t test of Ho: u1 - u2=0 using a-.01 and finds a significant difference between Xmean1 and Xmean2. From this we can infer.
a. a large difference between u1 and u2.
b. an important difference betwee u1 and u2.
c. u1 and u2 to be unequal.
d. all of the above.
C. µ1 and µ2 to be unequal.
To answer this question, let's first understand the scenario. Professor Casey performed a t-test of Ho: u1 - u2 = 0 using a significance level of 0.01. The result of the t-test indicated a significant difference between the sample means, Xmean1 and Xmean2.
Based on this information, we can infer that:
c. u1 and u2 are unequal.
This is because if the t-test resulted in a significant difference between Xmean1 and Xmean2, it suggests that the null hypothesis (Ho: u1 - u2 = 0) is unlikely to be true. In other words, the evidence supports the idea that the means of the two groups (u1 and u2) are indeed different.
Options "a. a large difference between u1 and u2" and "b. an important difference between u1 and u2" cannot be conclusively inferred from the given information. The significance of the difference between u1 and u2 is not explicitly mentioned, but we can infer that they are unequal based on the significant difference observed between Xmean1 and Xmean2.
Therefore, the correct answer is:
c. u1 and u2 to be unequal.