The weights (in kg) of 18 students are : 32, 28, 26, 25, 29, 27, 30, 42, 35, 33, 28, 26, 29, 38, 27, 32, 34, 36. The median of their weight is represented by M. If the weight 42 kg is replaced by 32 kg and weight 38kg is replaced by 29kg, and the median of their weights is represented by M' then find the value of M'- M
A) 0 kg
B) -0.5 kg
C) 0.5 kg
D) 1 kg
E) None of these
Answer is option (B)
Pls give me correct explanation of this answer. I will mark u as Brainliest
Answers
Answer:
29.5
Step-by-step explanation:
first turn 32, 28, 26, 25, 29, 27, 30, 42, 35, 33, 28, 26, 29, 38, 27, 32, 34, 36.
into 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 32, 32, 33, 34, 35, 36, 38, 42
tick the sides equally until there is one number left
if there is no number left, take the 2 middle number in the collection and take the mean of those 2 numbers.
25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 32, 32, 33, 34, 35, 36, 38, 42
29 and 30 are the numbers (29+30)÷2= 59÷2= 29.5
Answer:
25,26,26,27,27,28,28,29,29,30,32,32,33,34,35,36,38,42
M = 1/2 [ (n/2) th + (n/2 + 1)th term]
= 1/2 [ (18/2) th + (18/2 + 1) th term]
= 1/2 [ 9th + 10th term]
= 1/2 [ 29 + 30]
= 1/2 [ 59 ]
= 29.5
You can get the M just by taking the middle two terms & dividing it by 2.
If 42 is replaced by 32 & 38 by 29, then
25,26,26,27,27,28,28,29,29,29,30,32,32,32,33,34,35,36
M' = 1/2 [ (n/2) th + (n/2 + 1)th term]
= 1/2 [ (18/2) th + (18/2 + 1) th term]
= 1/2 [ 9th + 10th term]
= 1/2 [ 29 + 29 ]
= 1/2 [ 58 ]
= 29
The value of M' - M = 29 - 29.5 = -0.5
i.e (B) -0.5kg
And I also wanted to tell you that I made a mistake in my other answer of median ( option B median is 77). It just occurred to me while I was writing this answer. Pls report that answer or dlt if you can :) Sorry