Solution
For this case we can do the following:
X= amount of flakes
Y= amount of raisins
And for this case we have the following:
mu_x = 370, sd_x = 24
mu_y = 170, sd_x = 7
T = X+Y
And we want to find the following probability:
P( T> 515 gr)
The distribution of T is given by:
mu_T = 370 +170 = 540
[tex]sd_T=\sqrt[]{24^2+7^2}=25[/tex]And we can use the z score to solve the problem on this way:
[tex]P(T>515)=1-P(T<515)=1-P(Z<\frac{515-540}{25})[/tex][tex]1-P(z<-1)=1-0.841=0.16[/tex]