A psychology professor assigns letter grades on a test according to the following scheme. A: Top 10% scores, B: Scores below 10% and above the bottom 63%, C: Scores below the top 37% and above the bottom 20%, D: Scores below the top 80% and above the bottom 7%, F: Bottom 7 % of scores Scores on the test are normally distributed with a mean of 71.5 and a standard deviation of 9.5. Find the numerical limits for a D grade. Round your answers to the nearest whole number if necessary.

binomial distribution

median= 2

range = 7-0 = 7

how to find median?

no. of term=28

median=(28+1)/2=14.5th term

the 14th and 15th term are 2, therefore the median is (2+2)/2 = 2

answer: idk

step-by-step explanation:

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.