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Materials: Whiteboard Notebook Clicker Calculator Green Textbook. Warm Up. In one or two sentences explain what standard deviation tell you. 2. If a colony of 10951 emperor penguins, 6592 are male. What proportion are male? What ratio are female?. Today’s Theme….
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Materials: Whiteboard Notebook Clicker Calculator Green Textbook Warm Up In one or two sentences explain what standard deviation tell you. 2. If a colony of 10951 emperor penguins, 6592 are male. What proportion are male? What ratio are female?
Today’s Theme…. How confident are you???
If we play rock, scissors, paper, what is the true proportion of times each weapon wins? Let’s find out with a rather long, but simple example…
Rock – Paper – ScissorsWhat proportion of the time does Rock win?What proportion does scissors win?What proportion does paper win?
Groups of 3 Battle 10times against each person in your group Third person keeps track of which weapon won each round: until 30 battles complete Calculate percent each weapon wins Write down final percents for each weapon on the board and repeat rock Scissors Paper
1. What is the average proportion of times paper wins (based only on your two trials)? 3. What is the standard deviation for all trials? 2. What is the sample proportion for all trials? Sample proportion (a parameter) • A point estimate. Find by averaging all trials. • p= population proportion + random variation • Standard deviation =
point estimate • is a single number. No information on how close you are to the actual population parameter • interval estimate • Gives information about how close you are to the population parameter Upper Confidence Limit Lower Confidence Limit Point Estimate Width of confidence interval
What is the 95% confidence interval for the proportion of times paper wins? Click in the lower limit (when you subtract) Click in the upper limit (when you add) How confident are you??? Confidence Interval (CI) The probability that you capture the true population falling between two sets of values: lower and upper confident limit Lower Confidence Limit Upper Confidence Limit Point Estimate
How confident are you??? Typical level of confidence is 99%, 95%, 90% Each level associated with a different z-value: 99%: z = 2.58 95%: z = 1.96 90%: z = 1.64 Confidence Limits = Point Estimate ±(z)(stdv) Confidence Interval (CI)
2. What is standard deviation? 3. What is the upper confidence limit? 4. What is the lower confidence limit? 1. What is the sample proportion?
Explain to your partner…. What is a confidence interval?
Classwork Green Book Page 495 #9-1, 9-3, 9-5 Finish for Homework