D Question 6 10 pts We suspect that Method 1 for detecting impurities in iron ingots yields higher results than Method 2 for finding such impurities. We want to give a 95% confidence interval for the difference in the average number of impurities detected by the two methods. In order to obtain the confidence interval we measured the impurities of 3 ingots, employing both methods for each ingot. The results are presented in the table below. We let M1 denote the population average number of defects for Method 1 and /2 denotes the population average number of defects for Method 2. We wish to develop a confidence interval for Ad = M1-M2. Give the point estimate for /d . Ingot 1 Ingot 2 Ingot 3 Method 1 16 32 12 Method 2 12 26 10 0 3 0 4 O 2 0 5 O 18