The difference between the groups is:

(a) Unlikely to have occurred by sampling error, assuming the null hypothesis to be true (F(2,470)

= 387.806; p < 0.001)

(b) Unlikely to have occurred by sampling error, assuming the null hypothesis to be true (F(2,470)

= 14.565; p < 0.001)

(c) Likely to have occurred by sampling error, assuming the null hypothesis to be true (F(2,470) =

387.806; p < 0.001)

(d) Likely to have occurred by sampling error, assuming the null hypothesis to be true (F(2,470) =

14.565; p < 0.001)