(Q1): A company manufactures bags of cement, each expected to weigh 20 kg with a standard deviation of 4 kg. A construction company manager has purchased a large lot of these bags, and suspects that the average weight of the bags is below the advertised 20 kg. To confirm his suspicions, the manager sets up a hypothesis test at a 2.5% significance level. A random sample of 64 cement bags form the lot he purchased has an average weight of 19.5 kg. a) Write down the Null and alternate hypotheses. b) Should the manager reject the null hypothesis? c) Is this a 1-sided test or a 2-sided test ? ( i.e., 1-tailed or 2-tailed ?)