2 The lengths of a random sample of 50 roads in a certain region were measured.Using the results,a \(95 \%\) confidence interval for the mean length,in metres,of all roads in this region was found to be[245,263].
- Find the mean length of the 50 roads in the sample.
- Calculate an estimate of the standard deviation of the lengths of roads in this region.
- It is now given that the lengths of roads in this region are normally distributed.
State,with a reason,whether this fact would make any difference to your calculation in part(b).