Suppose a researcher decided to test a hypothesis that adding compost to tomato plants increases mean tomato mass. she knew the standard deviation of the mass of all tomato plants, so she chose a one-sample z ‑test using a simple random sample of 50 plants that received compost. she used a significance level of a=0.05. the power of her test to detect a difference in mean tomato mass of 25 g or more was 0.95. what is the probability, β , that the researcher will make a type ii error and fail to conclude that adding compost increases mean tomato mass when, in fact, adding compost increases mean tomato mass by 25 g or more?