According to the Australian Red Cross Blood Service, 49% of people in Australia have O group blood, 38% have A group blood, 10% have B group blood, and 3% have AB group blood. A random sample of people produces the frequencies in the table below: Blood type Frequency 0 450 A 420 B 90 AB 40 a) Do you doubt the proportions claimed by the Australian Red Cross Blood Service? Perform a suitable test at the 5% significance level. b) Determine if we can claim that the proportion that have O group blood is different from the proportion the Australian Red Cross Blood Service claims by 1. constructing a 95% confidence interval for the proportion that have O group blood, and 2. performing a test of significance at 5% significance level. Do you have the same conclusion from the confidence interval calculation as that concluded by the test done? Explain why or why not