If x was the amount of money Mr. Green had remaining, and y was the amount of money Mrs. Green had remaining, then:
x / y = 3 / 2
And, since they spent the same amount of money:
200 - x = 180 - y
We can solve this system of equations through substitution.
x = 3/2 y
200 - 3/2 y = 180 - y
20 = 1/2 y
y = 40
So Mrs. Green had $40 remaining. Since she started with $180, she must have spent $140. So that was the cost of the shirt. Let's check our answer by seeing how much Mr. Green had remaining and how it compares.
The score of 96 is 2 standard deviations above the mean score. Using the empirical rule for a normal distribution, the probability of a score above 96 is 0.0235. Therefore the number of students scoring above 96 is given by:
Here is how you do it.... You will subtract 500 minus 225 to get the number of tails. The number of tails is 275. Now, you know your ratio is 225:500. All you need to do is simplify it. 225 divided by 25 is 9 and 500 divided by 25 is 20. Now, the ratio that you have is 9:20.
