1) a normal population has mean= 9 and standard deviation=6. what proportion of the population is less than 20? 2) a normal population has mean=56 and standard deviation= 8. what is the 85th...

1)
a normal population has mean= 9 and standard deviation=6. what proportion of the population is less than 20?

2)
a normal population has mean=56 and standard deviation= 8. what is the 85th percentile of the population?

3)
the weight of a male baby is less than 2 months old in the united states is normally distributed with mean 11.5 pounds and a standard deviation of 2.7 pounds. find the 81st percentile of the baby's weight.