Discuss the below:
Q1) When does the t-statistic approximate the z-statistic? Please ask yourself this question before answering: for a probability level of 0.975 on a one-tailed probability distribution, what is z-score and what is t-statistic? Then ask yourself, when does the t-statistic approximates the z-statistic?
Q2) What does "pooling" standard deviations or pooling sample proportions mean?
Q3) What do we mean by dependent and independent samples?