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.