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5:04 am
The following table shows results of a quality inspection of a lot of 15 mirrors.
DefectsFrequency
0 6
1 1
2 4
3 3
4 1
The difference between the median number of defects and the average number of defects in the sample checked is between:
(A) -1 and 0
(B) 0 and 0.5
(C) 0.5 and 1
(D) 1 and 1.5
(E) 1.5 and 2
i dont get dis question.
5:48 am
Median is defined as the middle number when the numbers are ordered in ascending or descending order
So the above table can be re written as
0 0 0 0 0 0 1 2 2 2 2 3 3 3 4
The middle number in these 15 numbers above is 2 . Hence the median = 2
Mean is defined as the sum of the items divided by the total number of items
So the mean= { 0 * 6 + 1*1 + 2*4 + 3 *3 + 4 *1 } /15 = 22/15 = 1.45
The question asks for the difference between the median and mean which will be median – mean = 2 – 1.45 = .55
Hence option C should be the answer
12:33 pm
@ ivy dreamer
hey tnx 4 d rply . i guess dis section covers d statistics section . i cant find ny chapter related 2 stats in sarvesh kumar verma .were can i find a book related 2 stats 2 brush up d concepts. is it enough if i go through grade 6 to 10 bks n mths
11:40 am
I think you should be able to find questions on statistics on the internet. Alternatively, you can refer to the 8th-10th grade books.Practice standard deviation questions the most as they may appear.
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