1. Set up hypothesis tests for the following situations and explain your reasoning a. What are your null and alternate hypotheses? b. Is it one-tail or two-tailed? Why? c. Indicate whether it is a z-test or +test d. If a t-test is recommended, how many degrees of freedom should be used? (No need to calculate the t-tests or z-tests) a) The EU wants to examine statistics on refugees' ages. Historically, the mean age of refugees arriving in Europe is 31.5 years old with a standard deviation of 3.8 years. In 2015, the EU conducted a simple random sample of 400 recently arriving refugees and wants to determine whether their age has declined compared to the historical average. b) A monitoring station set up near the Panama Canal records daily passage of vessels. A researcher obtains the daily records for the most recent year to compare with the daily data from a period of five years ago, which shows a historical mean of 150 vessels per day and a standard deviation of 12. The older data can be treated as the population for purposes of this test. The researcher is investigating international trade and wants to determine whether the mean of daily passage has changed in the most recent one-year period. c) An IDEV student team is evaluating the effectiveness of a new OECD development assistance program in improving women's socioeconomic welfare in developing countries. Current data shows that women in developing countries earn on average $2.21 per day, and this daily income is believed to be normally distributed, but the population standard deviation is not known. The new program will be adopted only if it significantly increases women's daily income. Because of the limited funding for the team, it is expected that the sample will consist of only 25 women