Quiz 6

MATH106

Quiz 6

Directions:

• Read and sign the academic honesty certification statement below, then read the questions carefully and answer them to the best of your ability. You may write your answers on this sheet or on the sheet you do your work on, but PLEASE show your work! Answers shown without work will get no credit. Work shown with unclear derivations or key steps missing in the derivations of answers will not lead to full credit (even if the answer is correct).

Show your work!

• Evaluate manually and write/type it on the quiz document, or

• Provide scan/image of work done on calculator or other software, or

• Insert chart/graphic if using software that produces such objects.

1. Evaluate the probability of correctly guessing exactly 7 of the 10 questions on this quiz. Use probability of success (since you’ve got a 50-50 chance of guessing each single question correctly) and the binomial distribution probability formula

Answer: P(7) = ___________________________

2. & 3. The following full IQ scores were obtained by testing a group of children who live near a lead smelter and are exposed to high concentrations of lead in the environment:

2. Complete the following frequency table:

3. Using the 20 raw data scores at top of this page (NOT the frequency table), find the arithmetic mean; median; and mode(s), if any:

Answers: Mean ______________ Median _______________ Mode(s) ______________

4. & 5. A social psychologist gave a survey to 8 active members of a small political action group about how many hours they put into the group's activities each week. The results were as follows: 41, 24, 44, 33, 40, 41, 19, and 30.

4. Compute the arithmetic mean, median, and mode(s), if any (if none, so state)

Answers: Mean ______________ Median _________________ Mode ___________

5. Using the arithmetic mean as the sample mean, compute the sample variance s2 and

sample standard deviation s.

Answers: Variance ___________________ Standard Deviation __________________

6. – 7. A network security specialist records the number of incoming e-mails containing links that six randomly-selected network users receive in a day. Numbers are 65, 71, 88, 100, 73, and 71.

6. Compute the arithmetic mean; median; and mode(s), if any (if none, so state):

Answers: Mean ______________ Median _______________ Mode(s) _________

7. Using the arithmetic mean as the sample mean, compute sample standard

deviation s :

Answer: s = __________________________

8. Multiple Choice: Which histogram below accurately reflects 15 survey responses presented in the following frequency table?

HISTOGRAM A HISTOGRAM C

HISTOGRAM B HISTOGRAM D

Answer: __________________

9. One of the initial clinical trials of the anti-math anxiety drug SHOVITALL™ tested for the presence of headaches as a side effect. In the trial, 450 subjects were treated with 80mg of the drug, and 2.2% of the subjects developed headaches. In the binomial distribution of these 450 subjects, what are the mean and standard deviation? Use ∏ = 0.022

Answers: Mean = _______________ Standard Deviation = _________________

10. Multiple Choice: According to the American Chemical Society, there is a 0.9 probability that in the United States, a single randomly selected $1 dollar bill is tainted with traces of cocaine. Assume eight $1 dollar bills are randomly selected. What is the probability that at least six (6) of the $1 dollar bills randomly selected will be tainted with traces of cocaine?

1. P (≥ 6) = 0.962 C. P (≥ 6) = 0.149

2. P (≥ 6) = 0.750 D. P (≥ 6) = 0.813

Answer: _________________________

11. A normal distribution has a mean of 40 and a standard deviation of 5. 68% of the distribution can be found between what two numbers?

10