Qa) A researcher needs on average, 4 years to complete a research. A random sample of 12 researchers are taken, and the duration (in years) to complete their research are recorded in Table 1. Do these data support the statement that a researcher needs exactly 4 years to complete a research? (Use a = 0.01). %3D Table 1: Duration of research 2.5 4.2 3.0 4.5 5.0 4,3 2.5 2.0 3.5 3.3 5.5 7.0 Qb) During a monthly meeting at a company, a quality control manager mentioned that the average number of acceptable computer motherboards produced by a JMT machine is 1500 pieces per hour. In 70 randomly selected hours of production, they found that the mean and the standard deviation of the number of acceptable pieces are 1522 pieces and 150 pieces. Based on the sample taken, can you verify whether the quality control manager is true or not in mentioning the average number of 1500 pieces? (Test at 5.7% level of significance).