Mean of a,b,8,5,10 is 6 ⇒5a+b+8+5+10=6⇒a+b=7 Given that Variance is 6.8 ∴ Variance =n∑(Xi−A)2=5(a−6)2+(b−6)2+4+1+16=6.8 ⇒a2+b2=25a2+(7−a)2=25⇒a2−7a+12=0∴a=4,3 and b=3,4
The mean of the numbers a,b,8,5,10 is 6 and the variance is 6.80. Then which one of the following gives possible values of a and b ?
Held on 30 Apr 2008 · Verified 6 Jul 2026.
a=0,b=7
a=5,b=2
a=1,b=6
a=3,b=4
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