Correct Answer:Option A. 0.01
Solution:This is a problem of statistics and uses the concept of normal distributions. We need to convert the score of 90 into z-score and then find the desired probability from standard normal distribution table.
Converting 90 to z-score:

Now we are to find the probability of z score being more than 2.33. From the z-table the probability comes out to be 0.01.
Therefore, we can conclude that the probability of class average is greater than 90 is 0.01.
The answer equals 6.
Since 3 3/4 equals 15/4, when you divide you have to switch the numbers in the divisor and then you turn the equation into multiplication.
So then it will be 15/4 x 4/3.
15 x 4 = 60
4 x 3 = 12 so the answer is 60/12. But you have to simplify so half of 60/12 is 30/6 and then half of 30/6 is 15/3 then you have to pick the gcf of 3 and 15 which is 3.
15 divided by 3 equals 5.
3 divided by 3 equals 1 so 5/1 equals 5
Hope this helps! ;)