73. 'A researcher conducts a significance test every time she analyzes a new data set. Over time, she conducts 100 tests

a) Suppose the null hypothesis is uue in every case. What is the distribution of the number of times she rejects the null hypothesis at the 05 level?

b) Suppose she rejects the null hypothesis in seven of the tests. Is it plausible that the null hypothesis is correct in every case? Explain