Question

A researcher compares the effectiveness of two different instructional methods for teaching anatomy. A sample of 79 students using Method 1 produces a testing average of 67.2. A sample of 44 students using Method 2 produces a testing average of 58.5. Assume that the population standard deviation for Method 1 is 11.27, while the population standard deviation for Method 2 is 17.38. Determine the 95% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2.

Step 2 of 3 :  Calculate the margin of error of a confidence interval for the difference between the two population means. Round your answer to six decimal places.

Answer 1

				Point estimate of differnce '=x1-x2 =			8.700
				for 95 % CI value of z=			1.96
				margin of error E=z*std error =			5.705202
				lower bound=(x1-x2)-E =			2.994798
				Upper bound=(x1-x2)+E =			14.405202

from above:

margin of error of a confidence interval =5.705202 (please try 5.705097 if this comes wrong and reply)