Show all relevant work; use the equation editor in Microsoft Word when necessary.

 

1. Chapter 5, numbers 5.11, 5.13, 5.15, and 5.18
2. Chapter 8, numbers 8.10, 8.14, 8.16, 8.19, and 8.21

 

Finding Proportions

 

5.11 Scores on the Wechsler Adult Intelligence Scale (WAIS) approximate a normal curve with a mean of 100 and a standard deviation of 15. What proportion of IQ scores are

 

a) above Kristen’s 125?

 

(b) below 82?

 

(c) within 9 points of the mean?

 

(d) more than 40 points from the mean?

 

Finding Scores

 

5.13 IQ scores on the WAIS test approximate a normal curve with a mean of 100 and a standard deviation of 15. What IQ score is identified with

 

(a) the upper 2 percent, that is, 2 percent to the right (and 98 percent to the left)?

 

(b) the lower 10 percent?

 

(c) the upper 60 percent?

 

(d) the middle 95 percent? [Remember, the middle 95 percent straddles the line perpendicular to the mean (or the 50th percentile), with half of 95 percent, or 47.5 percent, above this line and the remaining 47.5 percent below this line.]

 

(e) the middle 99 percent?

 

5.18 The body mass index (BMI) measures body size in people by dividing weight (in pounds) by the square of height (in inches) and then multiplying by a factor of 703. A BMI less than 18.5 is defined as underweight; between 18.5 to 24.9 is normal; between 25 and 29.9 is overweight; and 30 or more is obese. It is well-established that Americans have become heavier during the last half century. Assume that the positively skewed distribution of BMIs for adult American males has a mean of 28 with a standard deviation of 4.

 

(a) Would the median BMI score exceed, equal, or be exceeded by the mean BMI score of 28?

 

(b) What z score defines overweight?

 

(c) What z score defines obese?

 

8.10 Television stations sometimes solicit feedback volunteered by viewers about a televised event. Following a televised debate between Barack Obama and Mitt Romney in the 2012 U.S. presidential election campaign, a TV station conducted a telephone poll to determine the “winner.” Callers were given two phone numbers, one for Obama and the other for Romney, to register their opinions automatically.

 

(a) Comment on whether or not this was a random sample.

 

(b) How might this poll have been improved?

 

8.14 The probability of a boy being born equals .50, or 1 / 2 , as does the probability of a girl being born. For a randomly selected family with two children, what’s the probability of

 

(a) two boys, that is, a boy and a boy? (Reminder: Before using either the addition or multiplication rule, satisfy yourself that the various events are either mutually exclusive or independent, respectively.)

 

(b) two girls?

 

(c) either two boys or two girls?

 

8.16 A traditional test for extra-sensory perception (ESP) involves a set of playing cards, each of which shows a different symbol (circle, square, cross, star, or wavy lines). If C represents a correct guess and I an incorrect guess, what is the probability of

 

(a) C?

 

(b) CI (in that order) for two guesses?

 

(c) CCC for three guesses?

 

(d) III for three guesses?

 

8.19 A sensor is used to monitor the performance of a nuclear reactor. The sensor accurately reflects the state of the reactor with a probability of .97. But with a probability of .02, it gives a false alarm (by reporting excessive radiation even though the reactor is performing normally), and with a probability of .01, it misses excessive radiation (by failing to report excessive radiation even though the reactor is performing abnormally).

 

(a) What is the probability that a sensor will give an incorrect report, that is, either a false alarm or a miss?

 

(b) To reduce costly shutdowns caused by false alarms, management intro-duces a second completely independent sensor, and the reactor is shut down only when both sensors report excessive radiation. (According to this perspective, solitary reports of excessive radiation should be viewed as false alarms and ignored, since both sensors provide accurate information much of the time.) What is the new probability that the reactor will be shut down because of simultaneous false alarms by both the first and second sensors?

 

(c) Being more concerned about failures to detect excessive radiation, someone who lives near the nuclear reactor proposes an entirely different strategy: Shut down the reactor whenever either sensor reports excessive radiation. (According to this point of view, even a solitary report of excessive radiation should trigger a shutdown, since a failure to detect excessive radiation is potentially cata-strophic.) If this policy were adopted, what is the new probability that excessive radiation will be missed simultaneously by both the first and second sensors?

 

8.21 Assume that the probability of breast cancer equals .01 for women in the 50–59 age group. Furthermore, if a woman does have breast cancer, the probability of a true positive mammogram (correct detection of breast cancer) equals .80 and the probability of a false negative mammogram (a miss) equals .20. On the other hand, if a woman does not have breast cancer, the probability of a true negative mammogram (correct nondetection) equals .90 and the probability of a false positive mammogram (a false alarm) equals .10. (Hint: Use a frequency analysis to answer questions. To facilitate checking your answers with those in the book, begin with a total of 1,000 women, then branch into the number of women who do or do not have breast cancer, and finally, under each of these numbers, branch into the number of women with positive and negative mammograms.)

 

(a) What is the probability that a randomly selected woman will have a positive mammogram?

 

(b) What is the probability of having breast cancer, given a positive mammogram?

 

(c) What is the probability of not having breast cancer, given a negative mammogram?

ADDITIONAL INSTRUCTIONS FOR THE CLASS

Discussion Questions (DQ)

• Initial responses to the DQ should address all components of the questions asked, including a minimum of one scholarly source, and be at least 250 words.
• Successful responses are substantive (i.e., add something new to the discussion, engage others in the discussion, well-developed idea) and include at least one scholarly source.
• One or two-sentence responses, simple statements of agreement, or “good post,” and responses that are off-topic will not count as substantive. Substantive responses should be at least 150 words.
• I encourage you to incorporate the readings from the week (as applicable) into your responses.

Weekly Participation

• Your initial responses to the mandatory DQ do not count toward participation and are graded separately.
• In addition to the DQ responses, you must post at least one reply to peers (or me) on three separate days, for a total of three replies.
• Participation posts do not require a scholarly source/citation (unless you cite someone else’s work).
• Part of your weekly participation includes viewing the weekly announcement and attesting to watching it in the comments. These announcements are made to ensure you understand everything that is due during the week.

APA Format and Writing Quality

• Familiarize yourself with APA format and practice using it correctly. It is used for most writing assignments for your degree. Visit the Writing Center in the Student Success Center, under the Resources tab in LoudCloud for APA paper templates, citation examples, tips, etc. Points will be deducted for poor use of APA format or absence of APA format (if required).
• Cite all sources of information! When in doubt, cite the source. Paraphrasing also requires a citation.
• I highly recommend using the APA Publication Manual, 6th edition.

Use of Direct Quotes

• I discourage overutilization of direct quotes in DQs and assignments at the Masters’s level and deduct points accordingly.
• As Masters’s level students, it is important that you be able to critically analyze and interpret information from journal articles and other resources. Simply restating someone else’s words does not demonstrate an understanding of the content or critical analysis of the content.
• It is best to paraphrase content and cite your source.

 

LopesWrite Policy

• For assignments that need to be submitted to LopesWrite, please be sure you have received your report and Similarity Index (SI) percentage BEFORE you do a “final submit” to me.
• Once you have received your report, please review it. This report will show you grammatical, punctuation, and spelling errors that can easily be fixed. Take the extra few minutes to review instead of getting counted off for these mistakes.
• Review your similarities. Did you forget to cite something? Did you not paraphrase well enough? Is your paper made up of someone else’s thoughts more than your own?
• Visit the Writing Center in the Student Success Center, under the Resources tab in LoudCloud for tips on improving your paper and SI score.

Late Policy

• The university’s policy on late assignments is 10% penalty PER DAY LATE. This also applies to late DQ replies.
• Please communicate with me if you anticipate having to submit an assignment late. I am happy to be flexible, with advance notice. We may be able to work out an extension based on extenuating circumstances.
• If you do not communicate with me before submitting an assignment late, the GCU late policy will be in effect.
• I do not accept assignments that are two or more weeks late unless we have worked out an extension.
• As per policy, no assignments are accepted after the last day of class. Any assignment submitted after midnight on the last day of class will not be accepted for grading.

Communication

• Communication is so very important. There are multiple ways to communicate with me: 
  • Questions to Instructor Forum: This is a great place to ask course content or assignment questions. If you have a question, there is a good chance one of your peers does as well. This is a public forum for the class.
  • Individual Forum: This is a private forum to ask me questions or send me messages. This will be checked at least once every 24 hours.