Using The Almighty Formula (attached)
Note the symbol ^ is used to denote a raise to power
Where from the equation given x^2-5x-7
With a,b,c coefficients
a=1 b=-5 c=-7
From the Almighty Formula
√b^2-4ac=√(-5)^2-4(-7)=√53
Substituting in the Almighty Formula
-(-5) ±√53/2(1)= 5±√53/2
x=5+√53/2 and x=5-√53/2
Answer:
As long as the sample size n is large enough: The average IQ of Americans in the sample will be normally distributed.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a random variable X, with mean and standard deviation
, the sample means with size n of at least 30 can be approximated to a normal distribution with mean
and standard deviation
So the correct answer is:
As long as the sample size n is large enough: The average IQ of Americans in the sample will be normally distributed.