Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.
The mean of a data-set is the <u>sum of all observations divided by the number of observations</u>.
In this problem:
- In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is
. - In the next n observations, mean of 1.
Hence, the mean is:

We want the mean to be of 0.9, thus:





3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.
A similar problem is given at brainly.com/question/25323941
Amount of car loan taken by Scott = $5500
Amount of loan paid back by Scott = $7370
Then
Amount of money paid as interest by Scott = (7370 - 5500) dollars
= 1870 dollars
Then
Percentage of interest given for the car loan = (1870/5500) * 100
= 1870/55
= 34 percent
So Scott had to pay a total interest rate of 34% in the four years.I hope the procedure is simple enough for you to understand and solve future problems.
Answer:

Step-by-step explanation:
In order to find the answer to this question you must simply divide.





Hope this helps