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:
they are 17 miles away from their campsite.
Step-by-step explanation:
we get the answer by adding the miles traveled north to the miles traveled west, and we get the total number of miles they traveled away from their campsite.
5 + 12 = 17
Answer:
30degrees
Step-by-step explanation:
Given
Exterior angle m<CDE = 7x - 19 degrees
interior angles are
m<BCD = 2x - 1
m<DBC = x+10
Since the sum of the interior angles is equal to the exterior, hence;
2x - 1 + x+10 = 7x - 19
3x + 9 = 7x - 19
3x - 7x = -19 - 9
-4x = -28
x = 28/4
x = 7
Get m<CDE
m<CDE = 7x - 19
m<CDE = 7(7) - 19
m<CDE = 49 - 19
m<CDE = 30degrees
