 #1
 370
 0
Statistics Question  Normal Distribution SOLVED
Hey, the question is shown in the attached document.
Mean = 79 Standard Deviation = 12
I dispise these questions, and i'm failing to grasp them at all.
I've done the first two parts fine, but it's part c i'm struggling on.
I've tried using the z function getting me to;
P (Z [tex]\leq[/tex] [tex]\frac{b}{12}[/tex] )  P ( Z [tex]\leq[/tex] [tex]\frac{a}{12}[/tex] ) = 0.375
But i've got no idea what i'm doing :/ this question has totally thrown me, all of the methods i've used replacing the 2nd equation into the first have given me useless answers, I can usually do these questions fine, but i'm struggling here, any help would be great!
Homework Statement
Hey, the question is shown in the attached document.
Homework Equations
Mean = 79 Standard Deviation = 12
The Attempt at a Solution
I dispise these questions, and i'm failing to grasp them at all.
I've done the first two parts fine, but it's part c i'm struggling on.
I've tried using the z function getting me to;
P (Z [tex]\leq[/tex] [tex]\frac{b}{12}[/tex] )  P ( Z [tex]\leq[/tex] [tex]\frac{a}{12}[/tex] ) = 0.375
But i've got no idea what i'm doing :/ this question has totally thrown me, all of the methods i've used replacing the 2nd equation into the first have given me useless answers, I can usually do these questions fine, but i'm struggling here, any help would be great!
Attachments

41.9 KB Views: 296
Last edited: