Mildred has seven grades on her report card. The overall average of these grades is 77%. After looking more closely at her report card, Addie realizes that her English grade was incorrectly recorded as 18% instead of 81%. What is Mildred's actual report card average

86

Step-by-step explanation:

Firstly,

Average = Sum/Number of Numbers

Since 7 grades' average is 77, so we can say:

77 = Sum/7

Hence, Sum = 77 * 7 = 539

Now,

81 - 18 = 63 [63 marks were recorded incorrectly. actual sum would be 63 more]

So,

Actual Sum should be 539 + 63 = 602

Actual Average = 602 / 7 = 86

Hence, actual report card average would be 86