Use a simple regression model to test the hypothesis
$$
H_0: \beta_1=0
$$
versus
$$
H_1: \beta_1 \neq 0
$$
with $\alpha=0.05$, given the following regression statistics.
a. The sample size is $35, S S T=100,000$, and the correlation between $X$ and $Y$ is 0.46 .
b. The sample size is $61, S S T=123,000$, and the correlation between $X$ and $Y$ is 0.65 .
c. The sample size is $25, S S T=128,000$, and the correlation between $X$ and $Y$ is 0.69 .