The mean starting salary for graduates in the spring of 2004 was $36,280. Assume that the distribution of starting salaries follows the normal distribution with a standard deviation of $3,300. What percent of the graduates have starting salaries between $35,000 and $40,000?
a. 5225
b. .0041
c. .1251
d. None of the above
2 answers
Copy and paste the question into Google and the answer is there. Looks like it will be d, but check it out yourself
Here is the math
(35,000<X<40,000)=P((35,000-36,280)/3,300<(X-36,280)/3,300<(40,000-36,280)/3,300)=P(-0.3879<Z<1.1273)
=P(Z<1.1273)-P(Z<-0.3879)=0.8702-0.3491= 0.5211
(35,000<X<40,000)=P((35,000-36,280)/3,300<(X-36,280)/3,300<(40,000-36,280)/3,300)=P(-0.3879<Z<1.1273)
=P(Z<1.1273)-P(Z<-0.3879)=0.8702-0.3491= 0.5211