In this video, we will learn questions based on Properties of Mean which came in JEE Main Exam in the year 2013, 2014, 2015 from the Topic STATISTICS.

We will discuss some important properties of mean and fast methods to apply those properties in the exam.

If each observation is multiplied / divided by n, then Mean gets multiplied / divided by n2

If a constant number n is added / subtracted to each observation, then the new mean is equal to old mean add / subtract n

Questions Discussed

JEE Main 2013

The mean of a dataset consisting of 20 observations is 40. If one observation 53 was wrongly recorded as 33, then the correct mean will be:

(A) 41 (B) 49 (C) 40.5 (D) 42.5

Answer: (A)

JEE Main 2013

In a set of 2n distinct observations, each of the observations below the median of all the observations is increased by 5 and each of the remaining observations is decreased by 3. Then the mean of the new set of observations:

(A) increases by 1 (B) decreases by 1 (C) decreases by 2 (D) increases by 2

Answer: (A)

Extra Question Discussed

If x ̅ be the mean of x1, x2 , … , xn then for a≠0, the mean of ax1, ax2,… , axn, x_1/a,x_2/a,……,x_n/a is

(A) (a+1/a) x ̅ (B) ((a+1/a) x ̅)/2 (C) ((a+1/a) x ̅)/2n (D) ((a+1/a) x ̅)/n

TRY YOURSELF Questions

JEE Main 2015

The mean of the data set comprising of 16 observations is 16. If one of the observation valued 16 is deleted and three new observations valued 3, 4 and 5 are added to the data, then the mean of the resultant data, is

(A) 16.8 (B) 16.0 (C) 15.8 (D) 14.0

[Answer (D)]

JEE Main 2015 Online

A factory is operating in two shifts, day and night, with 70 and 30 workers respectively. If per day mean wage of the day shift workers is Rs. 54 and per day mean wage of all the worker is Rs. 60, then per day mean wage of the night shift workers (in Rs.) is

(A) 75 (B) 69 (C) 66 (D) 74

[Answer (D)]

Share this Video – Spread Learning

Link to share: https://youtu.be/xOUkcGdn8jw

Visit our facebook page

https://www.facebook.com/coachenggg

Follow us on INSTAGRAM

https://www.instagram.com/coachengg

Follow us on Google Plus

https://plus.google.com/+coachengg4u

_________________________________________________________________________________

Some Important Links are given below:

Sum of Series IIT JEE Concepts Playlist Link

Permutation and Combination IIT JEE Concepts Playlist Link

Binomial Theorem IIT JEE Concepts Playlist Link

Complex Numbers Maximum and Minimum Value IIT JEE Concepts Playlist Link

Physics Formulae Revision Playlist Link

————————————————————————————————————————————-

Statistics Problems, Mean, Variance, What is Variance in Statistics? Learn the Variance Formula, Statistics – Calculating Variance, How to calculate Standard Deviation, Mean, Variance Statistics, How to calculate Standard Deviation and Variance, Properties of Variance, Properties of Variance and standard deviation, Properties of Standard Deviation and Variance, Coefficient of variation, Standard deviation and Coefficient of variation, IIT JEE main maths statistics part 3 video lectures online solutions, Statistics | Mathematics | Class 11 | IIT JEE Main + Advanced, IIT JEE main advanced statistics part 2 video lectures online

————————————————————————————————————————————-

Class 11 MATHS ONLINE VIDEO LECTURES, CBSE Class 11 ONLINE PREPARATION, MATHS ONLINE COACHING, CBSE Class 11 ONLINE STUDY MATERIAL, CBSE Class 11 ONLINE TUTORING, BEST ONLINE MATERIAL FOR Class 11, CBSE BOARD EXAM PREPARATION, CBSE Board Maths Exam PREPARATION, CBSE Board Maths Sample Test Paper, IIT JEE 2017 Preparation with JEE Syllabus, NATA PREPARATION, JEE Main 2017, CBSE Board 2017 exam, CBSE Board Maths Sample Test Paper, JEE Main 2017 Sample paper, NDA Maths Sample Paper, NDA Question Paper Maths, NDA 2016 Results, NDA Maths Online Preparation

source

please sir solve ncert question no 9.20 and 9.21 of mechanical properties of solid

nyc video sir

sir plz upload more videos

sir upload the solution of both of the questions came in JEE MAINS 2015 from statistics

thanks a lot

yes sir