Question 932333
can u help me to solve these three questions?

1. The salary of workers x in a certain company is approximately normally distributed with a mean of $ 2500 and a standard deviation of $ 50. The company would like to claim that 80 % of workers got salary within $c. Find the value of c that makes this statement true? 

2. The amount of rainfall x in a certain country in summer is approximately normally distributed with a mean of 3.8 ml and a standard deviation of 1.05, The members of weather forecast would like to claim that 86.5 % chance of rainfall is within c ml. Find the value of c that makes this statement true?
 
3. The grade Y in a certain subject is approximately normally distributed with a mean of 16 and a standard deviation of 5.71. The teacher would like to claim that 90.5 % of students got within Y marks. Find the value of Y that makes this statement true?