1. The problem is to find the t-value for a sample mean compared to the national average. Given: sample size $n=16$, sample mean $\bar{x}=74$, sample standard deviation $s=8$, population mean $\mu=70$. 2. The formula for the t-value is: $$t=\frac{\bar{x} - \mu}{s/\sqrt{n}}$$ 3. Calculate the standard error: $$SE = \frac{8}{\sqrt{16}} = \frac{8}{4} = 2$$ 4. Calculate the t-value: $$t = \frac{74 - 70}{2} = \frac{4}{2} = 2$$ 5. The obtained t-value is 2.00.