Final answer:
To find the critical value tα/2 needed for a confidence interval of level 99.9% and sample size 16, consult the t-table or use the calculator function invT(0.0005, 15), which gives a value of approximately 3.901.
Step-by-step explanation:
To find the critical value tα/2 needed to construct a confidenceinterval of the given level, we need to use the t-table or a calculator.
For a level of 99.9% and a sample size of 16, we need to find the critical value corresponding to the area in the tails of the t-distribution.
In this case, we can consult the t-table or use the calculator function invT(0.0005, 15), which gives us a value of approximately 3.901 as the critical value tα/2.