Question

Increasing the sample size while keeping the same confidence level has what effect on the margin of error?
A. Decreases the margin of error and hence decreases the precision
B. Decreases the margin of error and hence increases the precision
C. Increases the margin of error and hence decreases the precision
D. Increases the margin of error and hence increases the precision
E. None of the above

The regression line is the straight line that bests fits a set of data points according to what?
A. Greatest-squares criterion
B. Most accurate regression criterion
C. Least-squares criterion.
D. None of the above

Answer 1

B. For increase in sample size, margin of error decreases while precision increases.

C. Least square criterion, regression fits the data following the least square criteria. Least square means sum of squares of errors between actual and predicted values is to be minimised.