3 The weights of pebbles on a beach are normally distributed with mean 48.5 grams and standard deviation 12.4 grams.
- Find the probability that the mean weight of a random sample of 5 pebbles is greater than 51 grams.
- The probability that the mean weight of a random sample of \(n\) pebbles is less than 51.6 grams is 0.9332 . Find the value of \(n\).