The quiz grades of a math class are given. 83, 76, 68, 97, 68, 80, 89, 74, 75, 81, 91, 90 The grades are normally distributed wi
Yuki888 [10]
Answer:
the answer is c) 1.08
Step-by-step explanation:
Step1:
Formula for calculating z-score is;
Z= (x-mean)/standard deviation
where x is the value for which z-score is required
Step 2:
As asked in the question z-score for highest grade is required which is 91;
z= (91-81)/9.3
z=10/9.3
z=1.075
which is approximately;
z=1.08
F(x) = x² - 81
Finding f⁻¹(x) the inverse function
Let y = f(x) and solve for x.
y = x² - 81
y + 81 = x²
x² = y + 81
x = √(y + 81)
Recall f(x) = y, that means x = f⁻¹(y)
x = √(y + 81)
f⁻¹(y) = √(y + 81)
Therefore f⁻¹(x) = √(x + 81)
3.4+2.5+4=9.9
9.9/3=3.3
That makes 3.3 pounds per friend
If you have a maybe text book look in there it may give you the answer
