Answer
There is enough evidence to conclude that there is a linear relation between both explanatory variables: the concrete’s slump and the 7-day strength with the response variable, 28-day strength.
Work Step by Step
1) $H_0: β_1=0$ versus $H_1: β_1\ne0$
See the results obtained in item (b)
$t_0=-2.69$ with a P-value $=0.027\ltα=0.05$. Reject the null hypothesis.
2) $H_0: β_2=0$ versus $H_1: β_2\ne0$
See the results obtained in item (b)
$t_0=2.54$ with a P-value $=0.034\ltα=0.05$. Reject the null hypothesis.
