4 The masses, in kilograms, of chemicals \(A\) and \(B\) produced per day by a factory are modelled by the independent random variables \(X\) and \(Y\) respectively, where \(X \sim \mathrm {~N} ( 10.3,5.76 )\) and \(Y \sim \mathrm {~N} ( 11.4,9.61 )\). The income generated by the chemicals is \(
) 2.50\( per kilogram for \)A\( and \)\\( 3.25\) per kilogram for \(B\).

1. Find the mean and variance of the daily income generated by chemical \(A\).
2. Find the probability that, on a randomly chosen day, the income generated by chemical \(A\) is greater than the income generated by chemical \(B\).