Step-by-step explanation:
Let,
Marks in fourth test = x
We know that
Mean = Sum of observation/Total observation
=> 46 = Sum/3
=> 46 × 3 = Sum
=> 138 = Sum
Now,
=> 50 = Sum of three observation + x/4
=> 50 = 138 + x/4
=> 50 × 4 = 138 + x
=> 200 = 138 + x
=> 200 - 138 = x
=> 62 = x
Hence,
he should score 62 marks in fourth test
Answer:
62
Step-by-step explanation:
several ways of doing this, but I'm going to give the long and comprehensive method,
recall that mean = total sum of marks / number of tests
in the first case, we are given
mean = 46 and number of test = 3
from this we can find the total number of marks of 3 tests by simply substituting the given values into the formula above
mean = total sum of marks / number of tests
46 = total sum of marks / 3
total sum of marks = 3 x 46
total sum of marks = 138 (for 3 tests)
in the second case, we are told that the number of tests is now 4 and the mean is 50 marks, using the same formula, we can find out the new total sum of marks for 4 tests
mean = total sum of marks / number of tests
50 = total sum of marks / 4
total sum of marks = 4 x 50
total sum of marks = 200 (for 4 tests)
number of marks for 4th test
= sum of marks for 4 tests - sum of marks for 3 tests
= 200 - 138
= 62 (answer)
hope this helps
