Easy Statistics Lab

1MATH221 Statistics for Decision Making
Week 4 Lab
Name: _______________________
Statistical Concepts:
• Probability
• Binomial Probability Distribution
Calculating Binomial Probabilities
NOTE: For question 1, you will be using the same data file your instructor gave you
for the Week 2 lab.
1. Using the data file from your instructor (same one you used for the Week 2 lab),
calculate descriptive statistics for the variable (Coin) where each of the thirty-five
students in the sample flipped a coin 10 times. Round your answers to three decimal
places and type the mean and the standard deviation in the grey area below.
Mean:
Standard deviation:
NOTE: for questions 2-7, you will NOT be using the data file your instructor gave
you. Please follow the instructions given in each question.
Plotting the Binomial Probabilities
➢ For the next part of the lab, open the Week 3 Excel worksheet. This will be used for
the next few questions, rather than the data file used for the first question.
1. Click on the “binomial tables” workbook
2. Type in n=10 and p=0.5; this simulates ten flips of a coin where x is counting the
number of heads that occur throughout the ten flips
3. Create a scatter plot, either directly in this spreadsheet (if you are comfortable
with those steps), or by using the week 1 spreadsheet and copying the data from
here onto that sheet (x would be the x variable, and P(X=x) would be the y
variable.
4. Repeat steps 2 and 3 with n=10 and p=0.10
5. Repeat steps 2 and 3 with n=10 and p=0.90
6. In the end, you will have three scatter plots for the first question below.
2
2. Create scatter plots for the binomial distribution when p=0.50, p=0.10, and p=0.90
(see directions above). Paste the three scatter plots in the grey area below.
Calculating Descriptive Statistics
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.
Round all numeric answers to three decimal places.
3. List the probability value for each possibility in the binomial experiment calculated at
the beginning of this lab, which was calculated with the probability of a success being
½. (Complete sentence not necessary; round your answers to three decimal places)
P(x=0)
P(x=1)
P(x=2)
P(x=3)
P(x=4)
P(x=5)
P(x=6)
P(x=7)
P(x=8)
P(x=9)
P(x=10)
4. Give the probability for the following based on the calculations in question 3 above,
with the probability of a success being ½. (Complete sentence not necessary; round
your answers to three decimal places)
P(x≥2)
P(x>2)
P(5