Construct a $95 \%$ confidence interval for the population mean length of engineering conferences. (i) State the confidence interval, (Round your answers to two decimal places.) \[ (2.70 \vee 3.22,3) \] (ii) Sketch the graph. (Round your answers to two decimal places. Enter your $\alpha / 2$ to three decimal places.) \[ \frac{\alpha}{2}=\square \text { C.L. }=\square \times \frac{\alpha}{2}=\square \] (iii). Calculate the error bound. (Round your answer to two decimal places.) Enter a number Additional Materials

Step 1 ：The question is asking for a 95% confidence interval for the population mean length of engineering conferences. The confidence interval is given as (2.70, 3.22).

Step 2 ：The confidence level is 95%, which means the alpha level is 0.05. Half of this alpha level, or alpha/2, is 0.025.

Step 3 ：However, we can calculate the midpoint of the given confidence interval, which could be used as an estimate of the mean.

Step 4 ：Let's calculate the midpoint of the confidence interval. The lower limit is 2.7 and the upper limit is 3.22.

Step 5 ：\(\text{midpoint} = \frac{2.7 + 3.22}{2} = 2.96\)

Step 6 ：Final Answer: The midpoint of the confidence interval, which could be used as an estimate of the mean, is \(\boxed{2.96}\).