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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Statistics

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
Expert replies
by Apoorva@5 » Fri Jul 01, 2016 11:40 pm
The residents of Town X participated in a survey to determine the no. of hours per week each resident spent watching TV. The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours.The no. of hours that Pat,A resident of Town X,watched TV last week was between 1&2 standard deviation below mean. so, the no. of hours he watched TV last week is?
Join the discussion
Source: — Quantitative Reasoning |

by Brent@GMATPrepNow » Sat Jul 02, 2016 5:47 am
When posting, please provide the ENTIRE question, including the answer choices.
Here's a link with a nice solution: https://www.beatthegmat.com/an-issue-reg ... 75194.html

Also, here's a video that covers the necessary concepts/skills to answer this question: https://www.gmatprepnow.com/module/gmat ... /video/809

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion

by [email protected] » Sat Jul 02, 2016 8:59 am
Hi Apoorva@5,

In the real world, Standard Deviation is based on a rather 'thick' math formula; thankfully, the GMAT will never ask you to use that formula or perform a standard deviation calculation that is all that complicated. SD is a rather rare subject on Test Day (you'll likely see it on just one question) and you'll be tested more on your general knowledge of the concept than on anything else.

In this particular prompt, we're given the mean (21 hours) and the SD (6 hours). We're asked for a value that is BETWEEN 1 and 2 SDs BELOW the mean. Since SD goes in both 'directions' from the mean, we would have the following results:

1 SD away would be (21-6) = 15 and (21+6) = 27
2 SDs away would be 21-12) = 9 and (21+12) = 33

Since we're specifically asked for BELOW the mean, we'd be looking for an answer that was between 9 and 15.

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Join the discussion

by Matt@VeritasPrep » Sun Aug 06, 2017 10:47 pm
If the mean is 21 and the sd is 6, then

mean = 21
one sd below = 21 - 6 = 15
two sds below = 21 - 2*6 = 9

so the answer should be between 9 and 15.
Join the discussion