So we know that an average is the sum of the scores divided by the number of scores that were added together. In this case we are going to be dealing with 4 tests. So let's say x is the score for our fourth test. We can create this equation:

So then we need to simplify the top:

Then multiply by 4 on both sides to get rid of the denominator:

Then solve for x:

So now we know that Sam needs to score a 67 on the fourth test to have an average score of 50.
The first is yes and the second is no
Answer:
300 points
Step-by-step explanation:
160 + 20 = 180
180 would have been 60 percent
180/60 = 300
300 would have been needed to pass
Proven by:
300 * 60% = 180
180 - 20 = 160
Answer:
Step-by-step explanation:
let y represent number of years...
9 ft tall = (12 * 9) = 108 inches
10 ft tall = (12 * 10) = 120 inches
Type A : 9 ft (or 108 inches) and grows 6 inches per year..
108 + 6y
Type B : 10 ft (or 120 inches) and grows 3 inches per yr
120 + 3y
how many years will it take them to be the same height...so when will they be equal....so set them equal and solve for y
108 + 6y = 120 + 3y
6y - 3y = 120 - 108
3y = 112
y = 112/3
y = 37 1/3 years....or 37 years and 4 months <====
check...
108 + 6(37 1/3) = 120 + 3(37 1/3)
108 + 6(112/3) = 120 + 3(112/3)
108 + 672/3 = 120 + 336/3
672/3 - 336/3 = 120 - 108
336/3 = 112
112 = 112 (correct)