Answer:

Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the IQ scores of a population, and for this case we know the distribution for X is given by:
Where
and
If we standardize the variable with the z score given by:

We got a normal standard distribution with parameters 

Answer:

Step-by-step explanation:
we have
-----> equation A
----> equation B
we know that
The solution of the system of equations is the point 
so
The solution of the equation
is equal to the x-coordinate of the solution of the system of equations
therefore
The solution is 
-7 + (-4) at (less than -1)
-(3/2) at (less than -1)
-8/5 x -5/8 isn't less or greater than 1
(-5) / (-3) at (greater than I)
(-9)/6 at (less than 1)
Answer:
The unit rate is 1.28
Step-by-step explanation: Divide 3.84 by 3 and you get 1.28