A study found that, in 2017, 12% of Kenyan workers belonged to unions. Suppose a sample of 455 Kenyan workers is collected in 2018 to determine whether the proportion of union membership increased.

a. If the sample results for 2018 showed that 21.3% of the workers belonged to unions, at = 0.01 determine whether union membership increased in 2018. What is your conclusion? Use both P-value approach

b. Develop a 99% confidence level for the proportion of union membership in 2018

c. If we want to estimate the population proportion of union membership in 2018 with a margin of error of 0.75, what sample size should be used? Assume 96% confidence level. d. What is the Type I error in this situation?