Find the VALUE of or EVALUATE 7a - 9 when a = 10. (HINT: 7a means 7 times a which is 7 times 10)

Can you me find the missing length. i attached an image.

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%

Calculate the missing value. round the answer to on decimal place. start with 70, increase it by 21%, and end up with