Find the positive value of x if the standard deviation of the numbers 1, x + 1 is 6

Assessment: JAMB UTME - Mathematics - 1998 Subject: General Mathematics

Question 1 Report

Find the positive value of x if the standard deviation of the numbers 1, x + 1 is 6
Answer Details
mean (x) =  1 + x + 1 + 2 x + 1 3
=  3 x + 3 3
= 1 + x
X ( X − X ) ( X − X ) 2 1 − x x 2 x + 1 0 0 2 x + 1 x x 2 2 x 2
S.D =  ∑ ( x − 7 ) 2 ∑ f
=  ( 6 ) 2
=  2 x 2 3
= 2x2
= 18
x2 = 9
∴ x =  ±   9
=  ± 3

Download The App On Google Playstore

Everything you need to excel in your exams

Green Bridge CBT Mobile App
Personalized AI Learning Chat Assistant
200,000+ Exam Questions Across IGCSE, JAMB, WAEC & NECO
Over 3,900 Lesson Notes
Offline Support - Learn Anytime, Anywhere
Green Bridge Timetable
Literature Summaries & Potential Questions
Track Your Performance & Progress
In-depth Explanations for Comprehensive Learning