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JEE Main 202429 JanuaryMorning Shift
Exam
JEE Main
Year
2024
Date
29 January
Shift
Morning Shift
Subject
Mathematics
Chapter
Statistics

JEE Main 2024 · 29 January · Morning Shift · Mathematics · Statistics

If the mean and variance of the data 65, 68, 58, 44 , 48, 45, 60,...

If the mean and variance of the data 65,68,58,4465, 68, 58, 44, 48,45,60,α,β,6048, 45, 60, \alpha, \beta, 60 where α>β\alpha > \beta are 5656 and 66.266 . 2 respectively, then α2+β2{\alpha}^{2} + {\beta}^{2} is equal to

Correct answer

0

Step-by-step solution

Given: x¯=56\overset{¯}{x} = 56 and σ2=66.2{\sigma}^{2} = 66 . 2

We know that, σ2=∑(xi)2n−(x)2{\sigma}^{2} = \dfrac{\mathop{∑}_{}^{}{\left({x}_{i}\right)}^{2}}{n} - {\left(x\right)}^{2}

⇒652+682+582+442+482+452+602+α2+β2+60210−(56)2=66.2⇒ \dfrac{{65}^{2} + {68}^{2} + {58}^{2} + {44}^{2} + {48}^{2} + {45}^{2} + {60}^{2} + {\alpha}^{2} + {\beta}^{2} + {60}^{2}}{10} - {\left(56\right)}^{2} = 66 . 2

⇒α2+β2+2567810−(56)2=66.2⇒ \dfrac{{\alpha}^{2} + {\beta}^{2} + 25678}{10} - ( 56{)}^{2} = 66 . 2

⇒α2+β2+2567810=(3136+66.2)⇒ \dfrac{{\alpha}^{2} + {\beta}^{2} + 25678}{10} = \left(3136 + 66 . 2\right)

⇒α2+β2=32022−25678⇒ {\alpha}^{2} + {\beta}^{2} = 32022 - 25678

⇒α2+β2=6344⇒ {\alpha}^{2} + {\beta}^{2} = 6344

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