(! ) i have a set of five questions that i need answering. i'm offering 42 points for these questions about matrices and cramer's rule.

questions are numbered:
3
5
6
7
8

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%