• Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • examPAL
    Most awarded test prep in the world
    Now free for 30 days

    Available with Beat the GMAT members only code

    MORE DETAILS
    examPAL
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep

Probability- hair treatment

This topic has 1 expert reply and 3 member replies
jcnissi Junior | Next Rank: 30 Posts
Joined
12 Jun 2010
Posted:
18 messages
Upvotes:
1

Probability- hair treatment

Post Thu Nov 18, 2010 9:55 pm
I'm really good with math but unfortunately, statistics is my weakest point. I'm trying to do all sorts of statistic practice problems so that I can get better. Any help is greatly appreciated!

A particular hair treatment program has caused hair growth in 70% of its users. A random sample of 15 users is obtained. Using the Binomial Probability Distribution, determine the following probabilities:

a) That exactly 14 experienced hair growth.

b) That less than 9 experienced hair growth.

c) That more than 10 experience hair growth.

d) That 15 or more experience hair growth.

e) That 7 or less experienced hair growth.

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Matt@VeritasPrep GMAT Instructor
Joined
12 Sep 2012
Posted:
2640 messages
Followed by:
113 members
Upvotes:
625
Target GMAT Score:
V51
GMAT Score:
780
Post Thu Oct 12, 2017 9:18 pm
Not sure how this one got on the front page, but I do this stuff for my day job a lot. Here's an R function I wrote that will answer all five parts:

hairfun <- function(a,b,p,x){sum(sapply(a:b, function(p, x, k){p^k * (1-p)^(x-k) * choose(x, k)}, p=p, x=x))}

where a = the minimum number you want, b = the maximum number you want, p = the probability of each trial, and x = the number of trials, and sapply is found in the dplyr package.

For example, the answer to (2) would be found by running hairfun(0, 8, .7, 15), and the answer to (1) would be hairfun(14, 14, .7, 15).

  • +1 Upvote Post
  • Quote
  • Flag
Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!
goyalsau Legendary Member
Joined
02 Aug 2010
Posted:
866 messages
Upvotes:
31
Target GMAT Score:
700+
Post Fri Nov 26, 2010 11:47 pm
jcnissi wrote:
I'm really good with math but unfortunately, statistics is my weakest point. I'm trying to do all sorts of statistic practice problems so that I can get better. Any help is greatly appreciated!

A particular hair treatment program has caused hair growth in 70% of its users. A random sample of 15 users is obtained. Using the Binomial Probability Distribution, determine the following probabilities:

a) That exactly 14 experienced hair growth.

b) That less than 9 experienced hair growth.

c) That more than 10 experience hair growth.

d) That 15 or more experience hair growth.

e) That 7 or less experienced hair growth.
This is no way a Gmat question..............................

_________________
Saurabh Goyal
talk_to_saurabh@yahoo.com
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.

  • +1 Upvote Post
  • Quote
  • Flag
karanrulz4ever Master | Next Rank: 500 Posts Default Avatar
Joined
25 Jun 2010
Posted:
358 messages
Followed by:
4 members
Upvotes:
34
Test Date:
26/10/2010
Target GMAT Score:
730+
GMAT Score:
740
Post Fri Nov 26, 2010 10:15 pm
You do not have binomial probability questions in GMAT. If you are aiming for GMAT seriously, solve questions which have good chance of appearing on the GMAT test. Don't solve questions which have no chance of appearing.

_________________
My 740 Debrief

  • +1 Upvote Post
  • Quote
  • Flag
Night reader Legendary Member Default Avatar
Joined
27 Dec 2008
Posted:
1337 messages
Followed by:
10 members
Upvotes:
127
Test Date:
03/28/11
Post Fri Nov 26, 2010 10:43 pm
karanrulz4ever wrote:
You do not have binomial probability questions in GMAT. If you are aiming for GMAT seriously, solve questions which have good chance of appearing on the GMAT test. Don't solve questions which have no chance of appearing.
I agree with Karan, knowing how to solve the chay square stats or f-parameter will not help too much on GMAT.

Once, I tried to solve a work problem with three variables and two equations here; it took me a while. I even had to grab some dusty complex math staff of my sophomore uni year. Trying hard to apply matrix and Gauss solutions, I ended up with parameters for the third variable. Don't waste your time on rocket science what fingers can find.

_________________
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at http://www.gmatpill.com

  • +1 Upvote Post
  • Quote
  • Flag

Best Conversation Starters

1 lheiannie07 112 topics
2 ardz24 71 topics
3 Roland2rule 69 topics
4 LUANDATO 53 topics
5 swerve 45 topics
See More Top Beat The GMAT Members...

Most Active Experts

1 image description GMATGuruNY

The Princeton Review Teacher

154 posts
2 image description Rich.C@EMPOWERgma...

EMPOWERgmat

107 posts
3 image description Jeff@TargetTestPrep

Target Test Prep

106 posts
4 image description Scott@TargetTestPrep

Target Test Prep

98 posts
5 image description EconomistGMATTutor

The Economist GMAT Tutor

91 posts
See More Top Beat The GMAT Experts