Mathematics (AS & A Level) · Oct / Nov 2022 · Paper 63 · Question 7
9709
As printed in the paper
The question as text
In the past Laxmi’s time, in minutes, for her journey to college had mean 32.5 and standard deviation 3.1. After a change in her route, Laxmi wishes to test whether the mean time has decreased. She notes her journey times for a random sample of 50 journeys and she finds that the sample mean is 31.8 minutes. You should assume that the standard deviation is unchanged.
Read automatically from the paper; the printed page above is exact.
Show the answer and mark scheme
7(a)[5]
7(b)[5]
Make a free account to save your answers and see your weak topics and ask the AI why a wrong answer is wrong.