Question

Pls help with this !!!!!!!

Answer 1

Both methods assume a normal distribution of the data, but the z-tests are most useful when the standard deviation is known.

OR u can use , z-tests are used when we have large sample sizes (n > 30), whereas t-tests are most helpful with a smaller sample size (n < 30). Both methods assume a normal distribution of the data, but the z-tests are most useful when the standard deviation is known.