Answer:
66
Step-by-step explanation:
Use the formula for the mean of a set of numbers:
sum of the numbers
average = --------------------------------
count of numbers
Here we know that the average mark was 68, so we can write:
75 + 62 + 84 + 53 + x
average = 68 = ----------------------------------
5
or 274 + x
68 = -------------------
5
Solving for x, we multiply both sides by 5: 340 = 274 + x.
Subtracting 274 from both sides effectively isolates x:
340 = 274 + x
- 274 -274
------------------------
66 = x
The fifth student's mark was 66.
Answer:
-18/3
Step-by-step explanation:
Multiply the denominator and numerator by the same whole number.
Description: They didn't distribute the 3 to both x and 5, so they just had 3x+5.
actual problem:
3(x+5)=3x+15
3x+15=3x+15
subtract 3x from both sides and end up with
15=15
Correct Answer: 15=15
Answer:
314.2 cm^2
Step-by-step explanation:
The formula for the area of a circle of radius r is A = 3.14r^2.
With r = 10 cm, r^2 = 100 cm^2, and so the area of this circle is 314.2 cm^2, to the nearest tenth.
