Answer:
d. The population standard deviation is known.
Step-by-step explanation:
T-distribution or Z-distribution, which to use?
If we have the population standard deviation is known, we use the z-distribution.
Otherwise, if we only have the standard deviation for the sample, we use the t-distribution.
Which of the following is not appropriate to use the t-confidence interval for
When the population standard deviation is known, so letter d.
