If the average of 5 scores is X, what will be the new average if a 6th score of 100 is added?

To find the new average when a 6th score is added, we start with the information that the average of 5 scores is X. This means the total of those 5 scores can be calculated as 5 times the average, or 5X.

When we introduce a 6th score of 100, we need to determine the new total score. The new total will be the sum of the original total, which is 5X, plus the new score of 100. Therefore, the new total becomes 5X + 100.

To find the new average, we take the new total score and divide it by the total number of scores, which is now 6. The formula for the average is given by:

New Average = (Total of scores) / (Number of scores)

Substituting in our values:

New Average = (5X + 100) / 6

This representation aligns perfectly with the correct answer choice, confirming that the average of the 6 scores, after adding the score of 100, is indeed (5x + 100)/6. This formulation accurately reflects the way averages and totals interact when a new data point is introduced.