Study Guide for Problem #10

America Hernandez

Problem #10

According to the NIH, 32% of all women will fracture their hip by age 90. If 8 women age 90 are selected at random, what is the probability that exactly 5 of them will have suffered a hip fracture?

  • Step 1: begin by turning 32% into .32, This will be your success which is our (P).
  • Step 2: next we need to find the¬†failure¬†number¬†, so you have to subtract 1 – .32 = .68 this will be our (q)
  • Step 3: Since 8 women are selected at random, this value will be our (n)¬†or sample group
  • Step 4: Since the question is asking exactly 5¬†out of the 8 will have suffered a hip fracture, 5 will be our (x)
  • Step5: now that we have all our values we have to check¬†to see if ¬†n*p and n*q are greater than (>) 5 (this is a very important step and it must always be done for this type of problem to insure that you end up using the correct formula). So it will look like this np= 8 * .32= 2.56 ¬†nq=8 * .68= 5.44 ¬†**NOTE**¬†since one of our values is not greater than 5 (np=2.56) we have to use the binomial distribution equation:¬†nCx * p^x * q^n-x¬†
  • Step 6:¬†Now plug these values into the equation¬†like so:¬†n=8 , p= .32, q=.68, x=5 ¬† ¬† ¬† ¬† ¬† ¬† ¬†¬†8C5 ( .32 )^5 ( .68 ) ^8-5 = ¬†¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬†56 ¬† ¬†( .32 )^5 ( .68 ) ^3 = .059¬†

Hope my explanation was helpful and good luck on the final EVERYONE !!!! ūüôā¬†¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬† ¬†




Study Guide for Problem #13

Adriana Mandelburger

I will be explaining how to solve problem #13.

Question: A professor has found that the grades on the Statistics Final are normally distributed with a mean of 68 and a standard deviation of 15. If only the best 14% of the grade in the class will receive an A, what grade must a student obtain in order to get an A?

First what we want to do is write down the information that we are given:

Mean: 68

Standard Deviation: 15

Since it is a normal distribution problem, we know that the mean (68) should be placed in the middle of the bell curve that I encourage should be drawn in order to get a better picture of what the problem is asking for. We are trying to figure out what grade should the best 14 % of students get in order to receive an A. That is another way of saying the top 14% and so, we should be shading a small area on the far right side of the mean (68) on the bell curve.

After having this drawing, we now know that we have to find the z value that corresponds to the right side of this curve. This is how we will proceed into finding this z-value:

We have to convert 14% into a decimal= .1400

Next, since we are looking for the right side value, we do the following:

1-.1400= .8600

After getting .8600, we look for the two numbers close to it in the given tables. The two numbers closest to .8600 are .8599 and .8621. From these two numbers, now we have to see which one is the closest to .8600.

.8599 is only one number away and so we choose this one to work with. From here, we look at the z-score that this area falls into, and that would be 1.08.

From here, in order to find the x value that would give us our final answer, we must use the formula x= mean + (z-score)(standard deviation).

Once we plug in the numbers, it would look like this:

x= 68 + (1.08)(15)

Now let’s solve for x, by multiplying the two numbers in the parenthesis first and then proceeding with¬†the addition.

When solving the equation properly, x should equal 84.2

Therefore, a student must obtain at least an 84.2 in order to get an A.






Rubric (grading guide) – OpenLab Final Project

The link below will take you to the grading rubric for your OpenLab Final Project. ¬†The project is worth 15 points altogether, the equivalent of three OpenLab assignments, and the rubric explains how I will assign those 15 points (5 points in each of 3 different categories). You may wish to invest 15 minutes of your time in reading through it — knowing how I will grade the project can be a great benefit when you are setting out to complete it (knowledge is power!).

Grading Rubric for OpenLab Final Project: Final Exam Study Guide

OpenLab final project: Final Exam Study Guide

EDIT:  Since all the Final Exam Review problems are now spoken for, please choose a problem from Exam Review #3, problems 6-12.

List updated Thursday, May 16, 2pm to include current list of CLAIMED PROBLEMS (see the bottom of the post for the list).

Assignment (Due Thursday, May 16, 2:30pm).  Create a study guide for one problem on the final exam.  This project will take the place of all remaining OpenLab assignments (it will count for 3 assignments overall), and consists of the three tasks described below.

Your audience is your classmates and other CityTech students taking MAT 1272. 


  1. Choose a problem, and claim it by replying to this message.  Choose a problem from the final exam review sheet that you would like to work on Рbut do NOT choose problems #17, 21, or 26 (these will be covered in the final days of the semester).  Only one person may work on each problem, and they are assigned on a first-come, first-served basis.  To claim your problem, reply to this post and include your name and the problem number you want.  Please look through the replies that have already been posted Рif your problem is already taken, you must choose another.
  2. Solve the problem.  Write an explanation, in words, of each step of the problem, and then show the the results of each calculation. Include any advice you can think of that might help fellow students, for example how you knew what type of problem it was, or how you knew what to do next!
    Stuck?  Ask for help!  You are encouraged to talk to your classmates, to tutors, or to Mr. Reitz about your problem and solution.
  3. Create a new blog post with your solution. Do NOT reply to this post with your solution.  Instead, create a new blog post with your solution.  Your grade for this assignment will be based on your post.  Instructions for creating a blog post appear below.

Read the following instructions carefully and completely. 

You will create a new blog post on our OpenLab site. ¬†You create a new blog post by logging in to the site, and clicking on the gray circle with a “+” plus sign at the very top of the screen (and selecting “Post”). ¬†Once you have created and published a post, you can find it on the Home page of the site. You CAN make changes to a post, even after it appears on the site.

Your post should include the following:

TITLE: Study Guide for Problem # (insert your problem number here)

BODY: include the following in the body of your post

  • your name
  • the problem you chose to work on (please include the entire problem)
  • step-by-step solution, with explanations and results of each calculation

TAGS: please add the following tags to your post (using the box on the right). ¬†1. “study guide”, 2. topic (for example “hypothesis testing”, or “probability” – there are many options, and you can include more than one), 3. plus any other tags you think are appropriate

Don’t forget to click the blue “Publish” button on the right side of the screen to make your post public. ¬†You can also use the “Save Draft” option, which will save it without making it public (to find it later, go to the Dashboard and click “Posts” on the left side).

Feel free to post questions on the OpenLab if you have them.



CLAIMED PROBLEMS (Updated Thursday, May 16, 2:00pm):

1 Glen Moore
2 Julieann McGonigle
3 Tanzima Mursalin
4 Erica Press
5 Barbara George
6 Ram Rampersad
7 Brianna Mahoney
8 Jenny Soriano
9 Valerie Cabezas
10 America Hernandez
11 Craig Shaw
12 Anil Dipu
13 Adriana Mandelburger
14 Candice Wright
15 Anthony Marc
16 Melissa Alteon
17 xx
18 Garfield Gray
19 sessa
20 Dania Elder
21 xx
22 Zinaida Ashurova
23 Fatima Elmachatt
24 Mary Fung
25 Mohammed Ahmed
26 xx

Exam Review #3 (Problems 6-12 only)
6 Elizabeth Fitts
7 Laticia Bourne
8 Jacky Xu
12 Edward Zheng