A researcher compares the effectiveness of two differentinstructional methods for teaching electronics. A sample of 138students using Method 1 produces a testing average of 61 . A sampleof 156 students using Method 2 produces a testing average of 64.6 .Assume that the population standard deviation for Method 1 is 18.53, while the population standard deviation for Method 2 is 13.43 .Determine the 98% confidence interval for the true differencebetween testing averages for students using Method 1 and studentsusing Method 2. Step 2 of 3 : Calculate the margin of error of aconfidence interval for the difference between the two populationmeans. Round your answer to six decimal places.
