Roper is not using a simple random sample. The samples are calculated to get 500 males and 500 females. This would be very unlikely or improbable to take place in a simple random sample. The design that they are using is a stratified sampling (dividing the population into groups) with 2 strata and these are the males and females.
Answer:
160
Step-by-step explanation:
Constraint 1:
Let the total number of running shoes be = R
Let the total number of leather boots be = L
As the given number of total shoes are 48,
The equations becomes,
R + L = 48............(1)
Constraint 2:
As running shoes are twice the leather boots, equation becomes,
R = 2L..............(2)
Putting the value of R from equation(2) in equation (1)



Now putting the value of L in equation(2)
R= 2L
R = 
R=32
Hence, Amanda needs 16 pairs of leather boots and 32 pairs of running shoes.
Since absolute value is just taking the positive value of whatever you put in the function, it is 7.8 as well. Also, absolute value can be described as the distance from 0 on the number line. 7.8 is 7.8 "units" away from 0, thus meaning it is equal to 7.8.