Q71.For two data sets, each of size 5 , the variances are given to be 4 and 5 and the corresponding means are given to be 2 and 4 , respectively. The variance of the combined data set is (1) 11 (2) 6 2 (3) 13 (4) 5 2 2
What This Question Tests
This problem requires calculating the variance of a combined data set using the means and variances of individual data sets.
Concepts Tested
Formulas Used
Variance = (ฮฃx^2)/n - (mean)^2
Combined mean = (n1*mean1 + n2*mean2) / (n1+n2)
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๐ Question Details
- Chapter
- Statistics
- Topic
- Variance of combined data
- Year
- 2010
- Shift
- Unknown
- Q Number
- Q71
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
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