A teacher has an average score of 85 for her class of 20 students. If one student scores 95, what will be the new average if the class size increases to 21? (2023)
Practice Questions
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Q1
A teacher has an average score of 85 for her class of 20 students. If one student scores 95, what will be the new average if the class size increases to 21? (2023)
84
85
86
87
Total score = 85 × 20 + 95 = 1700 + 95 = 1795. New average = 1795 / 21 = 85.95, which rounds to 86.
Questions & Step-by-step Solutions
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Q
Q: A teacher has an average score of 85 for her class of 20 students. If one student scores 95, what will be the new average if the class size increases to 21? (2023)
Solution: Total score = 85 × 20 + 95 = 1700 + 95 = 1795. New average = 1795 / 21 = 85.95, which rounds to 86.
Steps: 5
Step 1: Calculate the total score of the class with the average score. Multiply the average score (85) by the number of students (20). This gives you the total score of the class before the new student joins.
Step 2: Add the score of the new student (95) to the total score you calculated in Step 1. This gives you the new total score for the class.
Step 3: Now, count the new total number of students in the class. Since one student has joined, the new class size is 21.
Step 4: To find the new average score, divide the new total score (from Step 2) by the new number of students (21).
Step 5: Round the result from Step 4 to the nearest whole number to get the final average score.
