MATH 221 Statistics – Lab Week 4

Plotting the Binomial Probabilities
1. Create plots for the three binomial distributions above. Select Graph > Scatter Plot and Simple then for graph 1 set Y equal to ‘one fourth’ and X to ‘success’ by clicking on the variable name and using the “select” button below the list of variables. Do this two more times and for graph 2 set Y equal to ‘one half’ and X to ‘success’, and for graph 3 set Y equal to ‘three fourths’ and X to ‘success’. Paste those three scatter plots below.

Calculating Descriptive Statistics
? Open the class survey results that were entered into the MINITAB worksheet.

2. Calculate descriptive statistics for the variable where students flipped a coin 10 times.Pull up Stat > Basic Statistics > Display Descriptive Statistics and set Variables: to the coin. The output will show up in your Session Window. Type the mean and the standard deviation here.

Mean:
Standard deviation:
Short Answer Writing Assignment – Both the calculated binomial probabilities and the descriptive statistics from the class database will be used to answer the following questions.
3. List the probability value for each possibility in the binomial experiment that was calculated in MINITAB with the probability of a success being ½. (Complete sentence not necessary)

P(x=0)
P(x=1)
P(x=2)
P(x=3)
P(x=4)
P(x=5)
4.

P(x=6)
P(x=7)
P(x=8)
P(x=9)
P(x=10)

Give the probability for the following based on the MINITAB calculations with the probability of a success being ½. (Complete sentence not necessary)

P(x?1)

P(x<0)

P(x>1)
P(4<x ?7)

5. P(x?4)
P(x<4 or x?7)

Calculate the mean and standard deviation (by hand) for the MINITAB created binomial distribution with the probability of a success being ½. Either show work or explain how your answer was calculated. Mean = np, Standard Deviation = Mean:
Standard deviation:

6. Calculate the mean and standard deviation (by hand) for the MINITAB created binomial distribution with the probability of a success being ¼ and compare to the results from question 5. Mean = np, Standard Deviation = 

Mean:
Standard deviation:
Comparison:

7. Calculate the mean and standard deviation (by hand) for the MINITAB created binomial distribution with the probability of a success being ¾ and compare to the results from question 6. Mean = np, Standard Deviation =

8. Explain why the coin variable from the class survey represents a binomial distribution.

9. Give the mean and standard deviation for the coin variable and compare these to the mean and standard deviation for the binomial distribution that was calculated in question 5. Explain how they are related. Mean = np, Standard Deviation =