What is the estimate of the sum of 304, 613, 840, and 434 using front end estimation?

How do you write something in scientific notation?

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%

Given: ∆mop p∆mop =12+4 3 m∠p = 90°, m∠m = 60° find: mp, mo