Question

From a series of 50 observations an observation of value 45 is dropped but the mean remain same. What was mean of 50 observation

Answer 1

Solution :

Question :

From a series of 50 observations an observation of value 45 is dropped but the mean remain same. What was mean of 50 observation ?

Let the observation mean be x , then Sum of 50 Observations is 50x

According to the Question :

⇒ [( 50x - 45)/49 ] x

⇒ 50x - 45 = 49x

⇒ x = 45

Therefore , From a series of 50 observations an observation of value 45 is dropped but the mean remain same , then the mean of 50 observations is 45

Answer 2

Let the observation mean be p        

Hence          

Sum of 50 Observations is 50p        

According to the Question :        

⇒ $\bf\huge\frac{50p-45}{49} \times p$   

⇒ 50p - 45 = 49p        

⇒ p = 45          

Mean of 50 observation = 45