Question

For Quon's first 6 quizzes he had a mean score of 33 points. After his 7th quiz his mean score was 32 points. After the 8th quiz the mean was 34. What was the difference in scores between his 7th and 8th quizzes

Answer 1

Answer:

Difference in scores between his 7th and 8th quizzes = 22

Step-by-step explanation:

Given: Mean score for first 6 quizzes is 33 points. After his 7th quiz his mean score was 32 points. After the 8th quiz the mean was 34.

To find: difference in scores between his 7th and 8th quizzes

Solution:

Mean scores = Total points scored in quizzes ÷ Number of quizzes

So,

Total points scored in quizzes = Mean scores × Number of quizzes

As mean score for first 6 quizzes is 33 points,

Total points scored in 6 quizzes = 6 × 33 = 198

As mean score for first 7 quizzes is 32 points,

Total points scored in 7 quizzes = 7 × 32 = 224

So,

7th score = Total points scored in 7 quizzes - Total points scored in 6 quizzes

               = 224 - 198

               = 26

As mean score for first 8 quizzes is 34 points,

Total points scored in 8 quizzes = 8 × 34 = 272

So,

8th score = Total points scored in 8 quizzes - Total points scored in 7 quizzes

               = 272 - 224

               = 48

Therefore,

Difference in scores between his 7th and 8th quizzes = 48 - 26

                                                                                          = 22