Search for: The variable X takes two values x1 and x2 with frequencies f1 and f2 respectively. If σ denotes the standard deviation of X, then σ2=The variable X takes two values x1 and x2 with frequencies f1 and f2 respectively. If σ denotes the standard deviation of X, then σ2=Af12x12+f22x22f1+f2−f1x1+f2x2f1+f22Bf1f2f1+f22x1−x22Cf1f2f1−f22x1−x22Dnone of these Register to Get Free Mock Test and Study Material +91 Verify OTP Code (required) I agree to the terms and conditions and privacy policy. Solution:We have, σ2=f1x12+f2x22f1+f2−f1x1+f2x2f1+f22⇒σ2=1f1+f22f12x12+f22x22+f1f2x12+x22−f12x12−f22x22−2f1f2x1x2⇒σ2=f1f2f1+f22x1−x22Post navigationPrevious: The S.D. of scores l, 2, 3, 4, 5, isNext: If α, β are the solutions of a tanθ+bsecθ=c, then tan (α+β)=Related content JEE Main 2023 Question Papers with Solutions JEE Main 2024 Syllabus Best Books for JEE Main 2024 JEE Advanced 2024: Exam date, Syllabus, Eligibility Criteria JEE Main 2024: Exam dates, Syllabus, Eligibility Criteria JEE 2024: Exam Date, Syllabus, Eligibility Criteria NCERT Solutions For Class 6 Maths Data Handling Exercise 9.3 JEE Crash Course – JEE Crash Course 2023 NEET Crash Course – NEET Crash Course 2023 JEE Advanced Crash Course – JEE Advanced Crash Course 2023