The average marks of 30 students was found to be 65. If the marks of two students were incorrectly entered as 38 and 54 instead of 83 and 45 respectively, then what is the correct average?

66.2

Avg of 30 students = 65

Wrong data = 38 +54 = 92

Correct data = 83 + 45 = 128

Diff. = 128 - 92 = 36

Correct avg. = 65+ \(\frac{36}{30}\) = 65 + 1.2 = 66.2