QUESTION 1 Table 1 shows the carbon monoxide (CO) measurements in Shah Alam air during 9am and 5pm for a randomly selected 10 days. Measurement are parts per million. The objective of the study is to see whether the CO concentrations at 9am is different from 5pm. Table 1 Day 9am 5pm 1 1.6 0.6 2.7 2.3 0.9 0.6 4 0.5 0.3 un 0.2 0.3 0.4 1.0 7 2.8 2.8 8 6.1 4.3 9 2.0 2.6 10 1.1 1.2 a) Calculate the mean and standard deviation of CO concentrations for both hours. b) Assuming population variances are equal conduct an appropriate test to test whether there is a significant different of CO concentrations between 9am and 5pm at o = 0.05. c) Based on your answers in (a) and (b) summarize the different levels of CO concentrations between the two hours