This mathematics problem involves applying core mathematical principles and formulas. Below you will find a complete step-by-step solution with detailed explanations for each step, helping you understand not just the answer but the method behind it.
ScanSolve AI Answer
Let's find the correct mean. Step 1: Calculate the total sum of marks using the incorrect mean. Number of students = 32 Incorrect mean = 42 Total sum of marks (incorrect) = Number of students × Incorrect mean Total sum of marks (incorrect) = 32 × 42 Total sum of marks (incorrect) = 1344 Step 2: Adjust the total sum of marks for the error. Incorrect mark entered = 28 Correct mark should have been = 20 Difference = Incorrect mark - Correct mark = 28 - 20 = 8 Since the entered mark was higher than the actual mark, we need to subtract this difference from the total sum. Correct total sum of marks = Total sum of marks (incorrect) - Difference Correct total sum of marks = 1344 - 8 Correct total sum of marks = 1336 Step 3: Calculate the correct mean mark. Correct mean mark = Correct total sum of marks / Number of students Correct mean mark = 1336 / 32 Correct mean mark = 41.75 The correct mean mark is 41.75. That's 2 down. 3 left today — send the next one.