The correct and complete question is shown below;
The random variable X denotes the GMAT scores of MBA students who were accepted to top MBA programs in Fall 2012. Assume that is normally distributed with a mean [tex]\mu_x[/tex] = 675 and a standard deviation [tex]\sigma_x = 30[/tex]
Typically, an MBA student who has a GMAT score above 710 is eligible for financial support. Given that a student is eligible for financial support, what is the probability that the student’s GMAT score is higher than 725?
Answer:
The probability that the student's GMAT score is higher than 725 = 0.3928
Step-by-step explanation:
From the given information:
Let X be the random variable that follows a normal distribution;
Then;
[tex]X \sim N( \mu_x = 675, \sigma_x = 30)[/tex]
To objective is to determine the probability that [tex]P(X > 725 | X > 710)[/tex]
[tex]P(X > 725 | X > 710)= \dfrac{P(X > 725 \cap X > 710 )}{P(X > 725)}[/tex]
[tex]\dfrac{P(X > 725 )}{P(X > 710)}=\dfrac{1 - P(X < 725) }{1- P(X < 710)}[/tex]
By using the EXCEL FORMULA: Â [tex]"= NORMDIST(x, \mu_x , \sigma_x , 1)"[/tex]
P(X< 725) = [tex]" = NORMDIST(725,675,30,1)"[/tex]
P(X< 725) = 0.9522
P(X< 710) = [tex]" = NORMDIST(710,675,30,1)"[/tex]
P(X< 710) =0.8783
[tex]P(X > 725 | X > 710)=\dfrac{1 - 0.9522}{1- 0.8783}[/tex]
[tex]P(X > 725 | X > 710)=\dfrac{0.0478}{0.1217}[/tex]
[tex]P(X > 725 | X > 710)=0.3928[/tex]