SOCR Courses 2008 2009 Stat13 1 Lab3b

STATS 13 Review Lab - October 21, 2008

Summary: This lab is going to serve as a review of what we did in the previous three labs.

Part 1: Histograms

1) Click the Charts tab on the SOCR website: [http://www.socr.ucla.edu], and click on the arrow next to Bar Charts then XYPlots. Then click on HistogramChartDemo and the DATA tab.

2) Open up another window, go to the SOCR website [http://www.socr.ucla.edu], and click the Modeler tab.

3) Click on the Data Generation button, and choose the Normal Distribution from the dropdown menu. Let’s make the sample size 100 and standard deviation 75. Mean stays 0.

4) Check the Raw Data box on the left side – this step is the simplest yet most important.

5) Hit the Sample button and click on the Data tab next to the Graphs tab.

6) Select all the data by holding Apple+A for Macs and Ctrl+A for PC. Press the COPY button at the top.

7) Go back to the window with the HistogramChartDemo. Press the PASTE button on the left hand side of the screen.

8) Click on the GRAPH tab and play around with the bin size at the bottom. Take a picture of the histogram you created by using the Print Screen command. Comment on the changes you see as you increase/decrease the bin size.

Part 2: Probability

1) Click on the Experiments tab on the SOCR website. We’re going to do the Coin Die Experiment again, so select it from the dropdown menu.

2) Set the distribution of both dice to skewed left (6 should have the most probability).

3) Set p = 0.8 and run 100 trials. Count the number of 6’s and take a picture of the graph.

4) Repeat Step 3 with p = 0.2. Make sure you take a picture.

5) Change the distribution of only the green die to skewed right (6 should have the least probability), and repeat steps 3 and 4. You should comment on changes and have 4 pics.

Step 3: Binomial Distribution

1) Click on the Experiments tab on the SOCR website. Select Binomial Coin Experiment.

2) Make sure n=20 and p=0.50.

3) Choose the Stop 10 option and press fast-forward. This will generate 10 simulations of 20 flips of the coin. Take a picture.

4) Choose the Stop 100 option and press fast-forward. This will generate 100 simulations of 20 flips of the coin. Take a picture. Compare the histogram with the histogram from Step 3.

5) Compare the histogram with the histogram of normal distribution.

Step 4: Coin Toss

1) This portion does not require you to do any calculations on SOCR.

2) Without using the equations of binomial distribution, solve the following problem: Let X equal the number of heads when you flip the coin 3 times. Calculate P(X>=2).