This is a question from my mid-session test, I can understand most of the others I got wrong, but I have no idea how to answer this.
Use the following to answer questions 14 & 15
JETSTAR's daily flight from Sydney to Broken Hill is on time seventy per cent of the time. Over the next 10 days:
Q15. The standard deviation of the relevant probability distribution (number of flights on time) is (closest to):
e) Impossible to calculate from the information given.
I'll avoid giving away my thinking to stop eliminating potential answers (because I got it wrong). Thanks folks.
P.s. This is all the information for the question.
Cool thanks - got it.
My problem was more reading the question. Just now it has clicked that it was a daily flight, I thought it was the total flights over 10 days, with the amount of flights being unknown.
As a result, I said (e), because I didn't have enough information to answer the question.
In fact N = 10 and I should be able to calculate it from there.