Mean of $$100$$ items is $$49.$$ It was discovered that three items which should have been $$60,\,70,\,80$$ were wrongly read as $$40,\,20,\,50$$ respectively. The correct mean is :
A.
$$48$$
B.
$$82\frac{1}{2}$$
C.
$$50$$
D.
$$80$$
Answer :
$$50$$
Solution :
Sum of $$100$$ items $$ = 49 \times 100 = 4900$$
Sum of items added $$= 60 + 70 + 80 = 210$$
Sum of items replaced $$= 40 + 20 + 50 = 110$$
New sum $$= 4900 + 210 - 110 = 5000$$
$$\therefore $$ Correct mean $$ = \frac{{5000}}{{100}} = 50$$
Releted MCQ Question on Statistics and Probability >> Statistics
Releted Question 1
Select the correct alternative in each of the following. Indicate your choice by the appropriate letter only.
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