- A46.8
- B56.8
- C51.8
- D103.6
Step-by-Step Solution
Wrong total used = . Remove the extra 46 and add the missing 64: correct total = 500 - 46 + 64 = 518. Correct mean = 518 / 10 = 51.8.
Answer: C) 51.8
A student computed the mean of 10 numbers as 50.
While adding, the number 46 was mistakenly added twice and the number 64 was left out completely.
There are actually 10 numbers. Find the correct mean.
Class 7Arithmetic MeanData Handling
Master this chapter in 30 minutes a day.
Don't just memorise the answer — build a daily practice habit.
Practice 5 Similar Questions Free →All Arithmetic Mean practice questions
More Class 7 Arithmetic Mean practice
11 observations have a mean of 35. The mean of the first 6 observations is 32 and the…The mean age of a class of 40 students is 13 years. When the teacher's age is included,…Suppose 6 numbers have a mean of 8. If 5 is added to the first number, 5 is subtracted…Meena's marks in 4 subjects average 72. To raise her average to 75 over 5 subjects, what…For a list of 20 numbers, the mean is 18. If 4 is added to each of the 20 numbers and…