Answer
No, see explanations.
Work Step by Step
a. State the hypotheses and identify the claim
$H_o: \mu=25.3$
$H_a: \mu\lt25.3$ (claim) (left tail test)
b. Find the critical value(s).
$\alpha=0.01, z_c=-3.1$
c. Compute the test value
$z=\frac{23.9-25.3}{6.39/\sqrt {100}}=-2.2$.
d. Make the decision.
Since $z\gt z_c$, we fail to reject the null hypothesis can do not support the claim.
e. Summarize the results.
At the 0.01 level of significance, it cannot be concluded that
the mean commuting time is less for this particular company.
