7 Over a period of time it has been shown that the mean number of vehicles passing a service station on a motorway is 50 per minute.
After a new motorway junction was built nearby, Xander observed that 30 vehicles passed the service station in one minute.
7
- Xander claims that the construction of the new motorway junction has reduced the mean number of vehicles passing the service station per minute.
Investigate Xander's claim, using a suitable test at the \(1 \%\) level of significance.
7 - For your test carried out in part (a) state, in context, the meaning of a Type 1 error.
7
- Explain why the model used in part (a) might be invalid.