Question

With respect to the z test (statistic) and the t test (statistic), each of the following are true, except:

1. When using either the z test or the t test, the sampling distribution should be positively skewed.

2. The z test is appropriate when the parameters of the population are known.

3. The t test is appropriate when the parameters of the population are unknown.

4. When using the z test or the t test depends of if μ and σ (or σ2) are known.

which one would be false?

Answer 1

This is false:

1. When using either the z test or the t-test, the sampling distribution should be positively skewed.

When using either the z-test or the t-test we assume that the underlying sampling distribution is symmetric i.e. normal. We never assume that the sampling distribution should be positively skewed.

All the remaining statements are true.

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