© 2013 Pearson Education, Inc. Active Learning Lecture Slides For use with Classroom Response Systems Introductory Statistics: Exploring the World through Data, 1e by Gould and Ryan Chapter 6: Modeling Random Events: The Normal and Binomial Models Slide 6 - 1

A probability distribution, sometimes called a probability distribution function (pdf) tells us A. all the possible outcomes of a random experiment B. the probability of each outcome C. Both A and B above D. None of the above Slide © 2013 Pearson Education, Inc.

True or False Discrete outcomes (or discrete variables) are numerical values that you can list or count. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False Continuous outcomes (or continuous variables) cannot be listed or counted because they occur over a range. A. True B. False Slide © 2013 Pearson Education, Inc.

Discrete Probability distributions can be A. tables. B. graphs. C. equations. D. All of the above. Slide © 2013 Pearson Education, Inc.

True or False The probabilities for a continuous-valued random experiment are represented as areas under curves, and are called a probability density curves. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False One reason the Normal model is the most widely used probability model for continuous numerical variables is that many numerical variables in which researchers have historically been interested have distributions for which the Normal model provides a very close fit. A. True B. False Slide © 2013 Pearson Education, Inc.

Which of the following represent a Normal Curve (or Normal Distribution)? Slide © 2013 Pearson Education, Inc. A. B. C. D.

True or False The Normal distribution is symmetric and unimodal (“bell-shaped”). A. True B. False Slide © 2013 Pearson Education, Inc.

True or False Because the Normal distribution is symmetric, the mean is in the exact center of the distribution. A. True B. False Slide © 2013 Pearson Education, Inc.

In the normal curve, if the standard deviation is large, then the Normal curve is A. wide and low B. narrow and tall C. wide and tall D. narrow and low Slide © 2013 Pearson Education, Inc.

In the normal curve, if the standard deviation is small, then the Normal curve is A. wide and low B. narrow and low C. wide and tall D. narrow and tall Slide © 2013 Pearson Education, Inc.

When you are finding probabilities with Normal models, the first and most helpful step is to A. sketch the curve B. label it appropriately C. shade in the region of interest D. All of the above in that order Slide © 2013 Pearson Education, Inc.

True or False The standard Normal model has a mean of 1 and a standard deviation of 0. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False The standard Normal model is an important concept, because it allows us to find probabilities for any Normal model. A. True B. False Slide © 2013 Pearson Education, Inc.

To convert a value to its z-score, A. Subtract the standard deviation, then divide by the mean. B. Add the mean, then divide by the standard deviation. C. Use the formula D. None of the above. Slide © 2013 Pearson Education, Inc.

To find the measurement from the percentile A. find the z-score from the percentile, then convert the percentile to proper units. B. find the z-score from the percentile, then convert the z-score to proper units. C. convert the z-score to proper units, then convert the percentile to a z-score. D. None of the above. Slide © 2013 Pearson Education, Inc.

To convert a z-score to proper units A. multiply the z-score times the mean and add the result to the standard deviation. B. multiply the z-score times the standard deviation and add the result to the mean. C. multiply the mean times standard deviation and add the result to the z-score. D. None of the above. Slide © 2013 Pearson Education, Inc.

True or False The Normal model is appropriate if it produces results that match what we see in real life. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False The binomial probability model is useful in many situations with discrete-valued numerical variables (typically counts, whole numbers). A. True B. False Slide © 2013 Pearson Education, Inc.

True or False A characteristic of a binomial model is that the number of trials is variable. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False A characteristic of a binomial model is that only two outcomes are possible at each trial. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False A characteristic of a binomial model is that the probability of success is the same at each trial. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False A characteristic of a binomial model is that the trials are dependent. A. True B. False Slide © 2013 Pearson Education, Inc.

Which of the following is a binomial experiment? A. Record the number of different eye colors in a group of 50 randomly selected people. B. A married couple decides to have children until a girl is born, but to stop at five children if they do not have any girls. How many children will the couple have? C. A student guesses on every question of a test that has 10 multiple-choice questions. Record the number of questions the student gets right. D. None of the above. Slide © 2013 Pearson Education, Inc.

True or False The shape of a binomial distribution depends on both n and p. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False Binomial distributions are symmetric when p = 0.5, but they are also symmetric when n is large, even if p is close to 0 or 1. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False For a binomial experiment the mean is µ = np A. True B. False Slide © 2013 Pearson Education, Inc.

True or False For a binomial experiment the standard deviation is A. True B. False Slide © 2013 Pearson Education, Inc.

True or False For a binomial experiment the mean is sometimes called the expected value because if you were to carry out a binomial experiment you would expect about µ successes. A. True B. False Slide © 2013 Pearson Education, Inc.

True or False For a binomial experiment, although we expect µ successes, we usually get µ give or take some amount. That give-or-take amount is what is measured by σ. A. True B. False Slide © 2013 Pearson Education, Inc.