4 A set of bathroom scales is known to operate with an error which is normally distributed. One morning a man weighs himself 4 times. The 4 values for his mass, in kg , which can be considered to be a random sample are as follows.
$$\begin{array} { l l l l }
62.6 & 62.8 & 62.1 & 62.5
\end{array}$$
- Find a \(95 \%\) confidence interval for his mass. Give the end-points of the interval correct to 3 decimal places.
- Based on these results, a \(y \%\) confidence interval has width 0.482 . Find \(y\).