Answer:
- <u>26</u>
Explanation:
The <em>average</em> is the mean. It is calculated adding all the values and dividing the sum by the number of values (data):
For the students who took the test the day before you, you can write:
Where n is the number of students who took the test first.
Thus, when the average was 69 the equation is:
When you take the test, the n + 1, the new average is 70, and the sum of the scores raised in 95 points:
Now you have a system of two equation and two unknowns, so you can solve it.
Clear the sum of the scores from the first equation:
Subsitute in the second equation:
Solve for n:
Thus, when you include your self the number of students who took the test was 25 + 1 = 26.