Hello, I need helo with these questions, please explain in detail how you did it.

Thank you

(1) Psychologists have found that stimulation during infancy has an effect on both cognitive and physical development. Image that a psychologist wants to investigate the effects of physical stimulation on body weight. The psychologist knows that the population mean weight for a two-year old is 26 pounds (u = 26) and that the population deviation is 4 (6 = 4). The psychologist contacts 16 couples (n = 16) with newborn children and asks to provide the newborns with physical stimulation for an hour a day. At age two years, the infants in the sample of 16 are weighed, and the average weight is found to be 30 pounds. The hypothesis tested is: Does physical stimulation significantly increase body weight? Use the alpha (a = ) 0.05 level of significance to test this hypothesis. Use a two-tailed test. (i) State the Null (Ho) and Research Hypotheses (H1): Ho: Ha: (ii) Calculate critical region using z-scores: (iii) calculate the standard error of the mean [standard distance between sample and population mean] OM n or - (iv) calculate z-score statistic M - u Z = - OM (v) Is the obtained z-score greater or lesser than the critical z-score? Is the z-score in the area of rejection of not? Is the z-score in the critical region? (vi) Do you accept or reject the Null hypothesis? (vii) Now calculate the effect size (Cohen's d:) d = (M - 1)(2) A psychologist wants to examine the effects of a new diet drug. The average amount of food without the drug that is consumed in the population is 1500 grams. The population deviation is 100 grams. Using a sample size of 25 it was found that the mean food intake while on the diet drug was 1450 grams. Perform the appropriate hypothesis test. Use a = 0.01. Test this using both two-tail and directional (one-tailed) tests. (i) State the Null (Ho) and Research Hypotheses (H1): Ho : Ha: (ii) Calculate critical region using z-scores Two-tailed a = 0.01 = One-tailed a = 0.01 = (iii) Calculate the standard error of the mean [standard distance between sample and population mean] n In (iv) Calculate z-score statistic M -u Z : (v) Is the obtained z-score in the critical region? Two-tailed: One-tailed: (vi) Do you accept or reject the Null hypothesis? Two-tailed: One-tailed: Now calculate the effect size (Cohen's d:) d = (M - U) O