We have a null hypothesis that u=3.75, but we are reluctant to accept this as the population value in case the true value is different.
an analysis tells us that the probability of rejecting the null hypothesis, if u is really 3.95, is .75.

this probability is: ) the power of the test against the alternative u=3.95b)the probability of a type 1 errorc) beta, which is equal to1 alpha (that is, one minus the significance level)d) the probability of a type 2 errore) equal to the significance level