Mean x=5.5=i=1∑10xi=5.5×10=55=i=1∑10xi2=371(∑xi)new =55−(4+5)+(6+8)=60(∑xi2)new =371−(42+52)+(62+82)=430 Variance σ2=10∑xi2−(10∑xi)2σ2=10430−(1060)2σ2=43−36σ2=7
For a statistical data x1,x2,…,x10 of 10 values, a student obtained the mean as 5.5 and i=1∑10xi2=371. He later found that he had noted two values in the data incorrectly as 4 and 5 , instead of the correct values 6 and 8 , respectively. The variance of the corrected data is
Held on 24 Jan 2025 · Verified 6 Jul 2026.
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