Given that out of 30 planted seeds only 9 of the m sprouted, then: Experimental probability =(number of occurrence of event)/(total number of trials made) =9/30 =3/10 thus the number of seeds that will sprout given that 20 seeds we planted will be: 3/10×20 =6 seeds
Well, since it is asking for an average, we have to add 78+89+87+96= 350... then we divide by 4 which would be 87.5 which IS greater than 80 :) and less than 90 :)