Twenty‐five students in a class take a test for which the average grade is 75. Then a twenty‐sixth student enters the class, takes the same test, and scores 70. The test average grade calculated with 26 students will

To find the new average grade with 26 students, we can follow these steps:

Step 1: Calculate the sum of the original test grades
The sum of the original 25 students' grades is obtained by multiplying the average grade (75) by the number of students (25):
Sum of original grades = 75 * 25 = 1875

Step 2: Add the new student's score to the sum
Now we need to add the new student's score (70) to the sum of the original grades:
Total sum = 1875 + 70 = 1945

Step 3: Calculate the new average grade
To find the new average grade, we divide the total sum by the number of students (26):
New average grade = Total sum / Number of students = 1945 / 26 = 74.81 (rounded to two decimal places)

Answer: The test average grade calculated with 26 students will be approximately 74.81.