A national grocer's magazine reports the typical shopper spends $11$ minutes in line waiting to check out. A sample of $21$ shoppers at the local Farmer Jack's showed a mean of $10\mathrm{.}0$ minutes with a standard deviation of $2\mathrm{.}2$ minutes.

Is the waiting time at the local Farmer Jack's less than that reported in the national magazine? Use the $0\mathrm{.}050$ significance level.

a$.$ What is the decision rule? $($Negative amount should be indicated by a minus sign. Round your answer to $3$ decimal places.$)$

Reject $H0$:$11$ and fail to reject $H1$:$<mn\; id="EditorElement\_2098112">1</mn><mn\; id="EditorElement\_2098113">1</mn>$ when the test statistic is

b$.$ Compute the value of the test statistic. $($Negative amount should be indicated by a minus sign. Round your answer to $2$ decimal places.$)$

Value of the test statistic