A researcher compares the effectiveness of two different instructional methods for teaching anatomy. A sample of 200200 students using Method 1 produces a testing average of 74.474.4. A sample of 245245 students using Method 2 produces a testing average of 87.587.5. Assume the standard deviation is known to be 11.7611.76 for Method 1 and 6.786.78 for Method 2. Determine the 95%95% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2.