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 1801:30 AM EDT
-02:30 AM EDT
Learn how Kamakshi achieved a GMAT 675 with an impressive 96th %ile in Data Insights. Discover the unique methods and exam strategies that helped her excel in DI along with other sections for a balanced and high score.
Sep 1808:00 PM PDT
-09:00 PM PDT
Video explanations + diagnosis of 10 weakest areas + 150+ short videos + study plan!
Sep 1712:30 AM EDT
-01:30 AM EDT
Thought your job leaves no time for GMAT prep? After multiple GMAT attempts and a demanding consulting job, Kshitij improved to 695 in under 2 months. Learn the mindset shifts, study strategy, and execution changes that made the breakthrough possible.
Sep 1902:30 AM EDT
-03:30 AM EDT
Tejas studied hard but kept repeating the same mistakes. After 3 attempts at 645, a focused 4-week strategy helped him identify and fix what was holding him back—leading to a 695 with just 12–15 hours of study per week.
Sep 2601:00 PM EDT
-04:00 PM EDT
Top scores are possible when you enroll in a powerful GMAT course, taught live online + 6 months access to TTP OnDemand video courses included. Class starts Saturdays Sept. 26, 2026 - Dec. 19, 2026, 1:00pm-4:00pm ES
Sep 2911:00 AM EDT
-01:00 PM EDT
" Description: Top scores are possible when you enroll in a powerful GMAT course, taught live online + 6 months access to TTP OnDemand video courses included! Class starts Tues/Thur Sept. 29, 2026 - Dec. 3, 2026, 11:00am-1:00pm EST
10 Feb 2017, 01:20
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
75%
(hard)
Question Stats:
44% (02:03) correct
56%
(02:07)
wrong
based on 62
sessions
History
Date
Time
Result
Not Attempted Yet
Last year at a particular day care center, 98% of the children were sick less than 40 days and 50% of the children were sick less than 25 days. If days sick was normally distributed among the children, what is the standard deviation?
A) 65
B) 48
C) 24
D) 15
E) 7.5
A) 65
B) 48
C) 24
D) 15
E) 7.5
11 Feb 2017, 01:10
Kudos
Bookmarks
The pattern follows the normal distribution.
50% children are sick less than 25 days = i.e. 1 SD Approx (it should be 68% if it follows normal distribution);
98% children are sick less than 40 days = i.e. 2 SD Approx (it should be 95% if it follows normal distribution);
Therefore, the difference is 40 -15 = 15% = this includes 1 SD from both side of the median (refer to the graph);
Hence, 1SD = 15/2 = 7.5 %;
Answer E.
50% children are sick less than 25 days = i.e. 1 SD Approx (it should be 68% if it follows normal distribution);
98% children are sick less than 40 days = i.e. 2 SD Approx (it should be 95% if it follows normal distribution);
Therefore, the difference is 40 -15 = 15% = this includes 1 SD from both side of the median (refer to the graph);
Hence, 1SD = 15/2 = 7.5 %;
Answer E.
Attachments
Normal-distribution-curve.jpg [ 26.46 KiB | Viewed 2759 times ]
11 Feb 2017, 02:54
Kudos
Bookmarks
duahsolo
Normal distribution and its 8.2-95.4-99.7 rule are NOT tested on the GMAT.
