Following from greatest to least 5 * 10 ^ 3 3.2 * 10 ^ 8 1.2 * 10 ^ 8 7 * 10 ^ 5

Answer question above and explain each step : )

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

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%