Question

We use a t distribution for inference about a population mean instead of the standard Normal distribution:

Answer 1

Answer: d. if we do not know the population standard deviation and must use the sample standard deviation.

Step-by-step explanation:

We use t-distribution is quite similar to distribution of z-score .

The interpretation of t-scores and z-scores are same.

T- distribution is used when the  data is not accurately normal and when the population standard deviation is  unknown.

In the absence of population standard deviation , we use the standard deviation of the sample.

So , We use a t distribution for inference about a population mean instead of the standard Normal distribution if we do not know the population standard deviation and must use the sample standard deviation.

Hence, the correct option is : d. if we do not know the population standard deviation and must use the sample standard deviation.