after her first four tests,Alisa has a mean score of 82.One more 100-point test is to be given in this class.All of the test scores are of equal importance.Is it possible for Alisa to raise her average (mean ) to 90?Explain.

To determine if it is possible for Alisa to raise her mean score to 90, we need to calculate the total points she has currently earned and the total points she needs to achieve the desired mean.

Currently, Alisa has taken four tests and has a mean score of 82. This means the total points she has earned from the four tests is 4 * 82 = 328.

Now, let's calculate the total points needed to achieve a mean score of 90. Since Alisa will be taking a fifth test worth 100 points, the total points needed would be (5 * 90) -100 = 450.

To find out if it is possible for Alisa to achieve a mean score of 90, we need to see if she can earn at least 450 points in total, including the fifth test.

Since Alisa has already earned 328 points, she needs an additional 450 - 328 = 122 points from the fifth test to achieve a mean score of 90.

Since the fifth test is worth 100 points, it is not possible for Alisa to raise her average to 90 because she would need to score more than the maximum possible points on the fifth test.

To determine whether it is possible for Alisa to raise her average (mean) to 90 after her first four tests, we can calculate the total points she has earned so far.

Given that Alisa has taken four tests and has a mean score of 82, we can find the total points she has earned by multiplying the mean score by the number of tests she has taken:

Total points earned = Mean score * Number of tests
Total points earned = 82 * 4 = 328

To find out if Alisa can raise her average to 90, we need to consider the maximum number of points she can potentially earn by taking the fifth test. As each test is worth 100 points, Alisa can achieve a maximum score of 100 on the fifth test.

To calculate the maximum possible total points after taking the fifth test, we can add the maximum score to the total points earned so far:

Maximum possible total points = Total points earned + Maximum score
Maximum possible total points = 328 + 100 = 428

Now, to determine Alisa's average score if she were to achieve the highest score possible on the fifth test, we divide the maximum possible total points by the total number of tests taken (5 tests in this case):

New average score = Maximum possible total points / Number of tests
New average score = 428 / 5 = 85.6

Based on this calculation, it is not possible for Alisa to raise her average score to 90 even if she scores 100 on the fifth test. The highest average score she can achieve is 85.6.

82 * 4 = 328

90 * 5 = 450

She needs 122 points on the last test. Is that possible?