The imposition of an integer restriction is necessary for models ...

[kellyjaisingh]

The imposition of an integer restriction is necessary for models where
 a. nonnegativity constraints are needed.
  b. variables can take negative values.
  c. the decision variables cannot take fractional values.
  d. possible values of variables are restricted to particular intervals.

Question 2

In interval estimation, as the sample size becomes larger, the interval estimate
 a. becomes narrower.
 
  b. becomes wider.
 
  c. remains the same, since the mean is not changing.
  d. gets closer to 1.96.

[bhavsar]

Answer to Question 1

c
RATIONALE: An integer linear program is a linear program with the additional requirement that one or more of the variables must be an integer.

Answer to Question 2

a
RATIONALE: In interval estimation, as the sample size becomes larger, the interval estimate becomes narrower.