Q:

A class of 25 students took a spelling test. Two students scored 90 each students scored 95 on each test, ten students scored 90 on each test, three students score80 on each test and one student scored 70.What is the average score of the spelling test rounded to one decimal place?​

Accepted Solution

A:
Answer:90.6Step-by-step explanation:I think you have the first line incorrect. You show below that 10 students scored 90, so the first line is that 2 students scored 100, not 90. The line with the score of 90 is missing the number of students, but we can find it out. Call that number x for now.Two students scored 100 each                                2x students scored 95 on each test                         xten students scored 90 on each test                    10three students score  80 on each test                    3and one student scored 70                                 +   1                                                                             x + 16There are x + 16 students accounted for. The total number of students is 25.x + 16 = 25x = 99 students scored 95 on each test.Now add up all the points scored by all students.Two students scored 100 each  (2 * 90)                2009 students scored 95 on each test (9 * 95)          855ten students scored 90 on each test (10 * 90)     900three students score  80 on each test (3 * 80)      240and one student scored 70 (1 * 70)                      +  70 Sum of all points:                                                  2245Now we find the average grade by dividing the sum of the points by the number of students.average = sum/number = 2265/25 = 90.6