Students collected money for a trip. Each of the 21 students contributed the same amount. How much did each student contribute, if they collected $260.40?

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%