Question

8. Mel's mean on 10 tests for the semester was 89. She complained to the teacher that she should be given an A because she missed the cutoff of 90 by only a single point. Explain whether it is clear that she really missed an A by only a single point if each test was based on 100 points. Explain how many points she actually missed.

Answer 1

Check Explanation

Step-by-step explanation

The mean of a group of numbers is the average of these numbers.

Mathematically, the mean is the sum of variables divided by the number of variables.

Mean = (Σx)/N

x = each variable

Σx = Sum of the variables

N = number of variables

So, when Mel's mean is 89 for 10 tests, this means

Mean = 89

N = Number of variables = 10

So, we can calculate the sum of all of Mel's scores

Mean = (Σx)/N

Cross multiply,

Σx = N [Mean]

Σx = 10 (89) = 890

For Mel to have an average score of 90 from 10 tests,

Mean = 90

N = Number of variables = 10

So, we can calculate the sum of all of Mel's scores

Mean = (Σx)/N

Cross multiply,

Σx = N [Mean]

Σx = 10 (90) = 900

So, we can see that Mel does not actually need 1 point to score an A (90), Mel needs 10 extra points gathered from the 10 tests, to get the extra average 1 point.

Hope this Helps!!!