A researcher compares the effectiveness of two different instructional methods for teaching physiology. A sample of 78 students using Method 1 produces a testing average of 89.5. A sample of 117 students using Method 2 produces a testing average of 55.9. Assume that the population standard deviation for Method 1 is 16.82, while the population standard deviation for Method 2 is 8. Determine the 99% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2. Find the point estimate for the true difference between the population means.

i think the answer would be c

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.