Mathematics (AS & A Level) · May / June 2021 · Paper 63 · Question 2
9709
As printed in the paper
The question as text
In the past, the time, in hours, for a particular train journey has had mean 1.40 and standard deviation 0.12. Following the introduction of some new signals, it is required to test whether the mean journey time has decreased.
Read automatically from the paper; the printed page above is exact.
Show the answer and mark scheme
2(a)[1]
2(b)[5]
2(c)[2]
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