Which is false?
(A) Given observations are = 4, 6, x, 8, 10, 13
Mean =
Now, given mean = 8
Sum of the observations = 4 + 6 + x + 8 + 10 + 13 = 8 × 6
⇒ 41 + x = 48
∴ x = 48 – 41 = 7
So, x = 7
The given statement is true.
(B) Given array = 59, 62, 65, x, x + 2, 72, 85, 99
n = 8 (even)
Median = 1/2 [value of (n/2)th term + value of (n/2 + 1)th term]
= 1/2 [value of 4th term + value of 5th term]
Median =
Given median = 67
67 = 2x + 2 = 67 × 2
2x + 2 = 134
2x = 134 – 2
X = = 66
So, x = 66
The given statement is true
(C) Given,
Observations are = 1, 3, 5, 7, 5, 2, 7, 5, 9, 3, p, 11
Mode = 5
Value of p = 7
We know that mode is the item which has highest frequency and in given statement 5 is the mode. If p = 7 then it will become the number with highest frequency. It means p can’t be equals to 7 as mode is 5.
So, the given statement is false.
(D) Given;
Mean of 10 observations = 15
Mean of 15 observations = 18
Mean of all 25 observation = 16.8
Now the sum of the observations;
Sum of 10 observations = 10 × 15 = 150
Sum of 15 observation = 15 × 18 = 270
Sum of 25 observation = Sum of 10 observations + Sum of 15 observations
Mean of 25 observations =
⇒ Mean =
⇒ Mean = 420/25
∴Mean = 16.8
So, the given statement is true.