Hello! I am looking for help in solving a set of questions for my STATS homework this week. I am having a hard time figuring out how to get the answers to these questions. Is there a formula that has to be used to find the estimated power in question one below? How do I find the estimated same size for question 3 below? I am a student who likes to know why the answer is what it is and not just the answer. I greatly appreciate the help-thank you!

Here are the 3 questions to one of my homework problems for this week:

1) A researcher studying the relationship between maternal age and length of breastfeeding in a sample of 75 primiparas found a correlation of .19, which was not statistically significant at the .05 level. What was the estimated power of the statistical test?

2) Conversely, what was the risk that a Type II error was committed (from question 1)?

3) If .19 is a good estimation of the population correlation, what sample size would be needed in a replication study to achieve power = .80 at = .05?

Thanks again!