A machinist is making engine parts with axle diameter of 0.7 cm. A random sample of 10 parts shows mean diameter 0.742 cm with a standard deviation…

A machinist is making engine parts with axle diameter of $\displaystyle 0.7$ cm. A random sample of $\displaystyle 10$ parts shows mean diameter $\displaystyle 0.742$ cm with a standard deviation of $\displaystyle 0.04$ cm. On the basis of this sample, find if you would say that the work is inferior. (Given $\displaystyle \mathrm{t}_9(0.05)=2.262$)