Statics
There are 3 questions attached. Please answer all of them. I have posted the questions below for a quick reference. There are also spreadsheets for Question 2 and Question 3 attached.
Question 1
Instructions:
· For your post you will make up a problem that uses binomial distribution similar to the example below. Try to have 3 scenarios. You do not need to solve your own problem.
· If you can, try a probability different from .5. In your problem, make sure that the probability stays the same for each trial!
· You will answer problems from classmates for your responses. Copy the question and your Excel formulas into your forum posts so your professor and classmates can check your work. Then write a brief summary of the results after the problem you copied in your post.
The following is just an example, DO NOT USE OR SOLVE.
Example initial post:
For this example, assume that a family has 8 children, and the probability that any one child is a boy is .5.
a) Find the probability that the family has exactly 5 boys.
b) Find the probability that the family has more than 5 boys.
c) Find the probability that the family has at most 5 boys.
For your response posts, here is how to solve these problems in Excel.
a) Find the probability that the family has exactly 5 boys.
Type into an Excel cell
=binom.dist(5,8,.5,False)
You should get .21875
b) Find the probability that the family has at most 5 boys.
Type into an Excel cell
=binom.dist(5,8,.5,True)
.855469 should be your answer
c) Find the probability that the family has more than 5 boys.
Type into an Excel cell:
=1-binom.dist(5,8,.5,True)
.144531 should be your answer
Notice that this answer is just 1 minus the answer from part b. Then, describe what these results mean by summarizing the results.
_____________________________________________________________________________________
Question 2
Initial Post – Instructions
Using the spreadsheet labeled QUESTION 2 EXCEL, go back and perform a linear regression. Find the equation of the linear equation that best fits your data and calculate the correlation coefficient (R). How does this compare to your analysis?
Response Post – Instructions
In your response posts, you will discuss the results and whether or not the results show a strong correlation or not. Discuss the value of R and what it means? What is ideal? Is this a good fit? Also, give examples in the real world where linear regression would make sense? When is a linear model the ideal model? In these cases what would you expect the value of R to be?
__________________________________________________________
Question 3
Initial Post Instructions:
- Choose a data set of fuel prices from the attached QUESTION 3 Excel file.
- Find the mean and standard deviation for the data set. Please do not try to do this by hand, but use the functions in Excel.
- Find the 95% Confidence Interval for your data.
Sample initial post:
- First find the mean and standard deviation. (
- Then type this in an excel cell =confidence.norm(0.05,stdev,samplesize) and hit enter. This is the E value. (Note: please use your standard deviation and sample size and not the words.)
- Set up your confidence interval: (mean-E, mean+E)
Formula you used above for the confidence interval:
The formula is E= zsubc * sigma / sqrt n
Where the left hand endpoint is xbar – E and the right hand endpoint is xbar + E
