The null hypothesis is that there is no change in the distribution of theOriginally Posted by aptiva
number of errors.
The critical z-score that a normal distributed RV exceeds with probability
0.95 is -1.64521. (a test with this critical value will reject the null hypothesis
if it were true 0.05 of the time, which is an alpha of 0.05)
The mean number of errors in a sample of size 50 persons under is 32.5,
and the SD of this is
Therefore we would reject the null hypothesis if the experiment had a mean
number of errors
But the results gave a mean number of errors of 32.2 which is less than
32.251, so we rejsct the null hypothesis using this test.