null hypo - pi = .1
alt hyp - pi not = .1
mu = .75
x bar = .1
z = ? sigma = ??
So how do we arrive at answer c... do we calculate a test statistic even? because definitely d can be eliminated becuase power of the test is > for a one sided than a two sided but it is uniform across both one sided tests... but that still leaves a- c..
Also, in a 2-tailed test , the prob of type 1 error has to be 10% ie 0.1. Option a says 0.005, which is wrong. eliminate a
But what about option B? it says ha <0.1, reject ho at 5% level and pr type 1 error = 0.05 and note that 400 mangoes 10% means 40 but we are told that from the sample 30 are rotten .. that's 7.5% so a test which says <0.1 could make sense
So can someone please explain why answer is option c... how can we calculate a test statistic here?