Normal tail and interval proportions with a shaded sketch and a replacement threshold from a lower percentile

The battery life, on a full charge, of a model of wireless earphones is normally distributed with mean \(26\) hours and standard deviation \(2.5\) hours.

1. Find the proportion of these earphones whose battery lasts more than \(30\) hours.[2]
2. 1. Find the proportion of these earphones whose battery lasts between \(22\) hours and \(29\) hours.
   2. Sketch a normal distribution curve and shade the region that represents the proportion found in part (b)(i).[5]
3. Earphones whose battery lasts less than \(t\) hours are replaced free of charge, and \(3\%\) of the earphones are replaced. Find the value of \(t\).[3]