Explanations

Question 1

Rejecting claims

Answer 1

1) X - u / o = F
In other words, calculate the variable x given with the mean and standard deviation.

2) P(Z > F )
Calculate the probability of Z in respect to the question. In this example, we’re calculating the probability of Z being bigger than the given number.

Question 2

Rejecting claims by significance

Answer 2

1) x - u / standard deviation / sqrt(n)

2) Either calculate two sided or one sided:
P(|Z| >= z) or P(Z >= 3)