Standardised value from a percentage, then the mean and standard deviation from a second related normal distribution

A bakery makes two types of loaf, standard and large. The masses of standard loaves are normally distributed with mean \(\mu\) grams and standard deviation \(\sigma\) grams. It is known that \(15\%\) of standard loaves have a mass of less than \(380\) grams.

1. It is given that \(\mu+B\sigma=380\), where \(B\in\mathbb{R}\). Find the value of \(B\).[3]

The masses of large loaves are also normally distributed. Their mean is \(60\) grams greater than the mean mass of standard loaves, and their standard deviation is \(1.5\) times the standard deviation of standard loaves. It is known that \(90\%\) of large loaves have a mass of more than \(410\) grams.

2. Find the value of \(\mu\) and the value of \(\sigma\).[4]