#### Answer

a)True.
b)False.
c)False.

#### Work Step by Step

a)If you use corresponding levels and significance levels, the three methods always lead to the same conclusion. Hence it is true.
b) The confidence interval method can lead to a different conclusion than the critical value and the P-value method. Hence it is false.
c)The confidence interval method can lead to a different conclusion than the critical value and the P-value method. Hence it is false.