Statistics · JEE Preparation Mathematics
For the data 4, 7, 9, 12, 15, 18, 21, calculate the first quartile, third quartile and coefficient of quartile deviation.
Practice question from Statistics (JEE Preparation Mathematics), with the correct answer and a step-by-step solution.
medium · Subjective · Q-416463
For the data 4, 7, 9, 12, 15, 18, 21, calculate the first quartile, third quartile and coefficient of quartile deviation.
Answer: There are 7 observations, so Q1 is the 2nd observation, 7, and Q3 is the 6th observation, 18. The coefficient of quartile deviation is (Q3 − Q1)/(Q3 + Q1) = (18 − 7)/(18 + 7) = 11/25 = 0.44.
Solution
For an individual series, is the th observation and is the th observation. With , these are the 2nd and 6th observations. Therefore, , , and the coefficient is .
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