Question

a tree farm owner measure 27 trees in his garden centre. mean diamter of 10.4 inches and standard dev of 4.7 inches.
Draw normal model for tree farm
What size would you expect the central 95% of trees to be?(Diagram required)
What percent of trees should be less than an inch in diameter?(diagram required)
What percent of trees should be between 4.9 and 10.4 inches.(diagram required)