To find the IQR you first need to write it in numerical order
77, 81, 83, 84, 86, 86, 88, 92
IQR is just Q3 - Q1
Q1 is the middle of the first have, since it has an even set of 4 numbers in the first half you need to take the average of the two middle ones.. which is 82
Q3 done the same process would be 87. 
87 - 82 = 5
IQR = 5
        
             
        
        
        
Answer:
4.4% of the population with IQ between 120 and 125. 
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 100
Standard Deviation, σ = 15
We are given that the distribution of IQ scores is a bell shaped distribution that is a normal distribution.
a) Let X be a person's IQ score. 
Then, density functions for IQ scores is given by:

b) P(population with IQ between 120 and 125.)
Formula:



 
        
             
        
        
        
Answer:
The constant of variation is $1.50
Step-by-step explanation:
Given
Point 1 (1,2)
Point 2 (5,8)
Required
Constant of Variation
Though the graph would have assisted in answering the question; its unavailability doesn't mean the question cannot be solved.
Having said that,
the constant variation can be solved by calculating the gradient of the graph;
The gradient is often represented by m and is calculated as thus

Where 

By substituting values for x1,x2,y1 and y2; the gradient becomes




Hence, the constant of variation is $1.50
 
        
                    
             
        
        
        
Answer:
y=16x ??
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
 
 
Step-by-step explanation:
 Given the following system of equations:
 
 In order to solve the system of equations using the Elimination Method, you can follow these steps:
 - Multiply the first equation by -6 and the secondd equation by 4.
 - Add both equations.
 - Solve for "y".
 Then:
 
 - Substitute the value of "y" into one of the original equations and solve for "x":
 