Find the variance of the given numbers: 36, 28, 45, and 51.

  1. 63.5
  2. 68.5
  3. 71.5
  4. 76.5

Answer (Detailed Solution Below)

Option 4 : 76.5
Free
RRB Group D Full Test 1
2.8 Lakh Users
100 Questions 100 Marks 90 Mins

Detailed Solution

Download Solution PDF

Mean is the average of the given numbers,

⇒ Mean = (36 + 28 + 45 + 51)/4 = 160/4 = 40

Variance is calculated by taking the average of the squares of the difference between each term and the mean,

⇒ Variance = [(36 - 40)2 + (28 - 40)2 + (45 - 40)2 + (51 - 40)2]/4

= [16 + 144 + 25 + 121]/4 = 306/4 = 76.5

∴ Variance of the given numbers = 76.5
Latest RRB Group D Updates

Last updated on Jun 2, 2025

-> The RRB NTPC Admit Card 2025 has been released on 1st June 2025 on the official website.

-> The RRB Group D Exam Date will be soon announce on the official website. Candidates can check it through here about the exam schedule, admit card, shift timings, exam patten and many more.

-> A total of 1,08,22,423 applications have been received for the RRB Group D Exam 2025. 

-> The RRB Group D Recruitment 2025 Notification was released for 32438 vacancies of various level 1 posts like Assistant Pointsman, Track Maintainer (Grade-IV), Assistant, S&T, etc.

-> The minimum educational qualification for RRB Group D Recruitment (Level-1 posts) has been updated to have at least a 10th pass, ITI, or an equivalent qualification, or a National Apprenticeship Certificate (NAC) granted by the NCVT.

-> This is an excellent opportunity for 10th-pass candidates with ITI qualifications as they are eligible for these posts.

-> The selection of the candidates is based on the CBT, Physical Test, and Document Verification.

-> Prepare for the exam with RRB Group D Previous Year Papers.

Get Free Access Now
Hot Links: teen patti tiger teen patti stars teen patti jodi