- (a) Null Hypothesis: \(H_0: p = 0.389\)
- (b) Alternative Hypothesis: \(H_1: p < 0.389\)
- (c) Type I Error: Rejecting \(H_0\) when it is true.
Thus, the final boxed answers are:
\[
\boxed{H_0: p = 0.389}
\]
\[
\boxed{H_1: p < 0.389}
\]
\[
\boxed{\text{Type I Error: Rejecting } H_0 \text{ when it is true.}}
\]