3.)You plan to conduct a survey to find what proportion of the workforce has been economically impacted by the covid19 virus. You decide on the 90% confidence level and state that the margin of error must be within 2% of the population proportion. If no prior information is available, how many people would you need to interview to meet your requirements? 4.) according to the local la union president, the mean income of plumbers is normally distributed with a mean of $60,000 and a population standard deviation of $6,000.An investigative reporter for the local television station took a sample to try to disprove that claim. The sample size consisted of 20 plumbers with a mean income of $62,500. At the 5% level of significance, is it reasonable to conclude that the mean income is different than $60,000? a) state the null and alternative hypotheses b) is this a one-tailed or two-tailed hypothesis text? c) find the critical value d) calculate the test statistic e) calculate the p-value f) what is your decision about the null hypothesis I need the answer after 1 hr thanks