If the calculated value of F is less than the critical value of ...

[TFauchery]

If the calculated value of F is less than the critical value of F, the experimenter should conclude that _____.
 
  a. chance is likely to have caused the results
  b. the treatment is likely to have caused the results
  c. chance alone cannot explain the results
  d. b and c

Question 2

If the calculated value of F is less than the critical value of f, the experimenter should conclude that _____.
 
  a. there is a significant difference among groups and proceed to a test of multiple comparisons.
  b. all groups are significantly different from one another
  c. only the highest and lowest group means are significantly different from one another
  d. none of the group means differ significantly from one another

[kaillie]

Answer to Question 1

A
In order to be significant, the calculated F must be equal to or greater than the critical F. If it is not, then chance is a likely explanation for the results.

Answer to Question 2

D
If the calculated value of F is smaller than the critical value of F, the experimenter must conclude that there are no significant differences between the means. Any differences observed are likely to be due to chance.