Math Is Fun Forum

MellyBigD

Member

Registered: 2018-03-13

Posts: 10

Probability Statistics: Please help!

Hi Guys

Please help me with the below exercise:

A well-known business school in Cape Town conducted a survey in 2013 amongst its MBA applicants to determine whether students apply to only one business school.  A sample of 2018 students was chosen and the following results were obtained: (rounded to 3 decimals)

Age    Did you apply to more than one school?    
    Yes    No    Total
23 and under    207    201    408
24-26    299    379    678
27-30    185    268    453
31-35    66    193    259
36 and over    51    169    220
Total    808    1210    2018

1.1) What is the probability that a randomly selected applicant is younger than 27                     [1]

1.2) What is the probability that a randomly selected applicant is 24-26 years old given that he/she did not apply to more than one school?                                                                 [3]

1.3) What is the probability that a randomly selected applicant is 24-26 years old or did not apply to more than one school?                                                                                       [3]

1.4) Is the number of schools applied to independent of age? Let A = “Yes” and B = “23 and under”.    [3]

zetafunc

Moderator

Registered: 2014-05-21

Posts: 2,436

Website

Re: Probability Statistics: Please help!

Hi MellyBigD,

Welcome to the forum. You have posted 4 threads asking for help, but you have not shown any attempts at the problems or given any pointers about where you are stuck. We will endeavour to help you as best you can, and we happily volunteer our time to do so, but we will not do your homework for you. Can you please show some attempts at these problems, or be specific about what exactly you are stuck on?

MellyBigD

Member

Registered: 2018-03-13

Posts: 10

Re: Probability Statistics: Please help!

1.1 P(A) = 408+678/2018 = 0.538
1.2 P(AlB) = 379/2018 / 1210/2018 = 0313
1.3 P(AUB) = P(A) + P(B) - P(AandB) =  (678/2018)+(379/2018)-(379/2018) = 0336
1.4 P(A) *P(B) = (207/808) * (408/2018) = 0.0517 interpretation

I can't, I am investing time again to go through the theory. I just have a mental block and under so much pressure, I want to do well and but it's frustrating if you just can't absorb the content!