2017 CSAT, all questions
UPSC Prelims 2017 · CSAT
Question 52: Basic Numeracy
If for a sample data Mean < Median < Mode then the distribution is
asymmetric
bskewed to the right
cneither symmetric nor skewed
dskewed to the left
AnswerUPSC’s answer is (d).
When Mean < Median < Mode, a long tail of low values drags the mean below the median and the mode, so the distribution has its tail on the left: it is skewed to the left (negatively skewed). Equal mean, median and mode would mean a symmetric distribution; Mean > Median > Mode would mean skew to the right. The mean always moves toward the tail.
Why each option is right or wrong
- (a) Symmetric would need mean, median and mode to be equal.
- (b) Right skew has mean > median > mode, the reverse order.
- (c) Unequal measures of centre mean it is not symmetric, so it is skewed.
- (d) Correct: mean below median below mode means a tail on the left.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2017, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.