Answer:
1. C. The researcher must compute an estimated standard error for the mean difference score to compute a t statistics.
2. B. 10
3. A. 12
Step-by-step explanation:
The degrees of freedom is number of independent variable factors that affect the range of parameters. The degrees of freedom is the calculation of number values that are free to vary. The degrees of freedom is calculated by N-1. Standard error is the estimated deviation of standard deviation from its sample mean distribution.