Testing whether a firm underpays its traders

Across the industry, trader pay has mean $132$ and standard deviation $25$. A prop firm's $40$ traders are paid an average of $122$. At significance level $0.01$ (critical value $z=-2.326$), is there evidence that the firm pays below the industry norm? Answer $1$ for yes and $0$ for no.

$1$ (yes). The one-sided statistic is $z=\dfrac{122-132}{25/\sqrt{40}}\approx-2.53$, which lies below $-2.326$, so the null of industry-standard pay is rejected.