Marbeya scored a 90% on the last exam; the class average was 70% with a standard deviation of 15%. Based on this, what do you know about Marbeya's z score

Afarmer has decided to divide his land area in half in order to plant soy and corn. calculate the area of the entire area so he knows how much soil is needed. each bag of soil covers 20 square yards. how many bags should the farmer purchase? (4 points) 1 bag 2 bags 3 bags 4 bags