help me please- Psychology Statistics

1. Explain the terms null hypothesis and alternate hypothesis. What is the difference between a directional alternate hypothesis and a non-directional alternate hypothesis? (total 4 points) 2. Use Z scores. For each part of the question, draw one normal curve (for a two-tailed test) or two curves (for a one-tailed test) that represent the region(s) where the Ho would be rejected, and the region(s) where the Ho would not be rejected. Label these regions as "Reject" or "R" and "Fail to Reject" or "FtR". Also label each curve with the appropriate z critical (Zcrit) value(s) that correspond to the region of rejection. (total 14 points) a) One-tailed test of significance (a = .05) (4 points) b) Two-tailed (nondirectional) test of significance (a = .05) (3 points) c) Two tailed (nondirectional) test of significance (a = .01) (3 points) d) Directional test of significant (a = .01) (4 points) 3. Use Z Scores. We draw a random sample from a population with a standard deviation of 15. In our sample, there are 150 observations, and the mean of the sample is 30. Determine the two values between which we would be 95% confident that the population mean would fall (i.e., a 95% confidence interval). In doing so, show the formula and the values of the variables in the formula. Show any calculations. Report your final answer using proper APA notation. (total 6 points)