Answer
No. See explanations.
Work Step by Step
a. State the hypotheses and identify the claim.
$H_o: \mu\geq10$
$H_a: \mu\lt 10$ (claim, left tail test)
b. Find the critical value(s).
$\alpha=0.05, z_c=-1.645$
c. Compute the test value.
$z=\frac{9.25-10}{2}=-0.375, P=0.354$
d. Make the decision.
Since $P\gt \alpha$, we do not have enough evidence to reject the null hypothesis and support the claim.
e. Summarize the results.
We can not conclude that the claim is justified.
