Compared to the independent t, the paired t for a given sample size always

Compared to the independent t, the paired t for a given sample size always
 
  a. has fewer degrees of freedom
  b. has more degrees of freedom
  c. uses degrees of freedom which are independent of the sample size
  d. none of these, since when sample sizes are fixed, so too are the degrees of
   freedom

Question 2

The Levene test may only be calculated with nominal data.
 
  Indicate whether the statement is true or false

Question 3

The population effect size is estimated in the numerator of the t ratio.
 
  Indicate whether the statement is true or false

Question 4

Using a repeated-measures design with a separate control group, helps to
  prevent
 
  a. sampling error
  b. score dispersion
  c. individual differences
  d. confounding variables