Mathematics (AS & A Level) · May / June 2022 · Paper 61 · Question 7
9709
As printed in the paper
The question as text
In the past, the mean time for Jenny’s morning run was 28.2 minutes. She does some extra training and she wishes to test whether her mean time has been reduced. After the training Jenny takes a random sample of 40 morning runs. She decides that if the sample mean run time is less than 27 minutes she will conclude that the training has been effective. You may assume that, after the training, Jenny’s run time has a standard deviation of 4.0 minutes.
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Show the answer and mark scheme
7(a)[1]
7(b)[3]
7(c)[2]
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