Answer:
Diameter=60.79
Step-by-step explanation:

So we are given that the mean is 42% and the sd (standard deviation) is 8%
Assuming our data is normal we can use the 68-95-99 rule
So one thing you should realize is that 42% + 8% is 50% which is passing. That is one standard deviation higher. So we use:
100 - 68 - 13.5 - 2.35 - 0.15 = 16. That means 16% of students passed the test. Which is terrible. They probably need to hit the books more.
Anyways if you have any question feel free to message me!
Hopes this helps!
F(x)=2x+4/3
Replace f(x) by y:
y=2x+4/3
Solving for x:
y-4/3=2x+4/3-4/3
Subtracting the two terms on the left side of the equation:
(3y-4)/3=2x
Dividing both sides of the equation by 2:
[(3y-4)/3]/2=2x/2
[(3y-4)/3]*(1/2)=x
[(3y-4)*1]/[(3)*(2)]=x
(3y-4)/6=x
x=(3y-4)/6
Replace "x" by "f^(-1) (x)" (inverse function) and "y" by "x":
f^(-1) (x) = (3x-4)/6 Inverse function
Then, for x=6
f^(-1) (6) = [ 3(6)-4]/6
f^(-1) (6) = (18-4)/6
f^(-1) (6)= 14/6
f^(-1) (6) = 7/3
Her hair will have grown 6 after 7/3 = 2.33 months
1.923 * 10 ^ -35 is the answer I got, however you did not specify any formatting to the question, so others may get a completely different answer