Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Sep 1506:30 AM PDT
-07:30 AM PDT
Solve GRE practice problems covering Quant (One answer choice and multiple answer choice), Data Interpretation, Text Completion, Sentence Equivalence, and Reading Comprehension Problems.- Sep 15
07:30 AM PDT
-08:30 AM PDT
Solve 30 GMAT Focus practice problems covering Problem Solving, Data Sufficiency, Data Insights, Reading Comprehension, and Critical Reasoning. Take this GMAT practice quiz live with peers, analyze your GMAT study progress, and more. 
Sep 1201:30 PM IST
-11:30 PM IST
With brand new features like:AI-driven Planner tool, 850+ data Insights practice questions and GMAT Focus Edition Adaptive mock tests with ESR+ analysis and personal mentor support, our course is the most comprehensive course for GMAT Focus Edition.- Sep 16
08:30 AM PDT
-09:30 AM PDT
Are you stuck at a score and looking for effective score improvement strategies to achieve your target on GMAT? Meet Rajat, who improved his GMAT score by an incredible 70 points in just 12 days(and less than 50 hours of study) with GMATWhiz! - Sep 17
10:00 AM PDT
-11:00 AM PDT
In this video, Mayank Srivastava, Founder of Experts' Global, explains all the details about ISB PGP applications for 2024-25. 
Sep 2001:00 PM EDT
-02:00 PM EDT
Have you ever wondered how to score a PERFECT 805 on the GMAT? Meet Julia, a banking professional who used the Target Test Prep course to achieve this incredible feat. Julia's story is nothing short of an inspiration.- Sep 21
11:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test. 
Sep 2210:00 AM EDT
-11:00 AM EDT
More and more TTP students are earning impressive scores on the GMAT. Now is the perfect time to join the many GMAT students who made the switch to TTP and surpassed their wildest expectations on test day.
What is the variance of set X, which contains only consecutive even in
[#permalink]
05 Aug 2021, 01:30
05 Aug 2021, 01:30
2
Bookmarks
Expert Reply
Show timer
00:00
A
B
C
D
E
Difficulty:
45%
(medium)
Question Stats:
60% (01:17) correct
40%
(01:15)
wrong
based on 90
sessions
What is the variance of set X, which contains only consecutive even integers?
(1) X consists of 10 terms.
(2) The range of X is 18.
(1) X consists of 10 terms.
(2) The range of X is 18.
Director
Joined: 02 Jul 2017
Posts: 644
Given Kudos: 333
Location: India
Concentration: Strategy, Technology
GMAT 1: 730 Q50 V39
GMAT 2: 710 Q50 V36
Re: What is the variance of set X, which contains only consecutive even in
[#permalink]
Updated on: 05 Aug 2021, 05:55
Updated on: 05 Aug 2021, 05:55
(D) is the answer IMO
Standard deviation/variance depends on the relative distribution of elements wrt mean so knowing pattern how elements are distributed and how m many total elements in the set exist should be sufficient to find SD/ variance
Statement (1) X consists of 10 terms.
We know elements are consecutive even integers i.e say 2, 4, 6,.....20 or 4, 6,8.....22
SD and variance can be computed
Sufficient
Statement (2) The range of X is 18.
Range = 18
Terms are consecutive even integers i.e we can find number of terms
nth term = first term + (n-1)*2
no of terms =\(\frac{(last term - first term )}{2}\) +1 = \(\frac{18}{2}\) + 1 =10
sufficient
Standard deviation/variance depends on the relative distribution of elements wrt mean so knowing pattern how elements are distributed and how m many total elements in the set exist should be sufficient to find SD/ variance
Statement (1) X consists of 10 terms.
We know elements are consecutive even integers i.e say 2, 4, 6,.....20 or 4, 6,8.....22
SD and variance can be computed
Sufficient
Statement (2) The range of X is 18.
Range = 18
Terms are consecutive even integers i.e we can find number of terms
nth term = first term + (n-1)*2
no of terms =\(\frac{(last term - first term )}{2}\) +1 = \(\frac{18}{2}\) + 1 =10
sufficient
Bunuel
What is the variance of set X, which contains only consecutive even integers?
(1) X consists of 10 terms.
(2) The range of X is 18.
(1) X consists of 10 terms.
(2) The range of X is 18.
Originally posted by sumitkrocks on 05 Aug 2021, 04:17.
Last edited by sumitkrocks on 05 Aug 2021, 05:55, edited 1 time in total.
Last edited by sumitkrocks on 05 Aug 2021, 05:55, edited 1 time in total.
Senior Moderator - Masters Forum
Joined: 19 Jan 2020
Posts: 3127
Given Kudos: 1511
Location: India
Schools: Cranfield (A) Warwick MiM "23 (M)
GPA: 4
WE:Analyst (Internet and New Media)
Re: What is the variance of set X, which contains only consecutive even in
[#permalink]
05 Aug 2021, 04:45
05 Aug 2021, 04:45
2
Kudos
Standard Deviation = Range/4
Variance = (SD)^2
Statement 1:
Set X = 10 units.
Let unit 1 = X
Unit 2 = X+2
Unit 10 = X+18 (you can count any 10 consecutive even integer)
Range = 18
SD = 4.5
Variance = 20.25
(Sufficient)
Statement 2:
Range = 18
SD = 4.5
Variance = 20.25
(Sufficient)
Answer should be D
Posted from my mobile device
Variance = (SD)^2
Statement 1:
Set X = 10 units.
Let unit 1 = X
Unit 2 = X+2
Unit 10 = X+18 (you can count any 10 consecutive even integer)
Range = 18
SD = 4.5
Variance = 20.25
(Sufficient)
Statement 2:
Range = 18
SD = 4.5
Variance = 20.25
(Sufficient)
Answer should be D
Posted from my mobile device
