BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

The lifetime of all the batteries produced by a certain company in a year have a distribution that is symmetric about

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 7187
Joined: Thu Sep 07, 2017 4:43 pmFollowed by: 23 members
by BTGmoderatorDC » Wed Jul 08, 2020 7:47 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

The lifetime of all the batteries produced by a certain company in a year have a distribution that is symmetric about the mean m. If the distribution has a standard deviation of d, what percent of the distribution is greater than m+d?

(1) 68 percent of the distribution lies in the interval from m-d to m+d, inclusive
(2) 16 percent of the distribution is less than m-d



OA D

Source: GMAT Prep
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Legendary Member
Posts: 2214
Joined: Fri Mar 02, 2018 2:22 pmFollowed by: 5 members

Re: The lifetime of all the batteries produced by a certain company in a year have a distribution that is symmetric abou

by deloitte247 » Fri Jul 10, 2020 8:27 am
Given that the distribution is symmetric about the mean m, this means that 50% of the distribution is above and below the mean
- Distribution also has a standard deviation of d

Statement 1 => 68% of the distribution lies in the interval from m - d to m + d, inclusive
100% - 68% = 32%
32% is less than m-d and more than m+d
As the distribution is symmetric about the mean 50% of 32% would be more than m+d
i.e 50/100 * 32 => 1/2 * 32
= 16%; would be greater than m+d
Statement 1 is SUFFICIENT

Statement 2 => 16% of the distribution is less than m-d
Recall that 50% of the distribution is above and below the mean, so if 10% of the distribution is less than m-d then 10% will be greater than m+d
Statement 2 is also SUFFICIENT

Since each statement alone is SUFFICIENT,
Answer = D
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1