STAT 110 - Section 5 Lecture 28

1. STAT 110 - Section 5 Lecture 28 Professor Hao Wang University of South Carolina Spring 2012 TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAAAAA

2. Final Exam – 9am-12pm, Wednesday, 04/25 Bring your ID, number 2 pencils, and a non-programmable/non-graphing calculator if you think you will need one. YOU MAY NOT USE A TI-83 OR YOUR PHONE. The practice final is NOT representative of all of the possible questions!!!

3. Final Exam – 9am-12pm, Wednesday, 04/25 E-mailed me before this Friday about taking the final late (5:30pm – 8:30 pm Wednesday 04/25)

10. The City of West Columbia wants to survey its adult citizens . To do this they use the list of all registered voters who have listed phone numbers. They contact 400 of those people and find that 228 favor improving the river-front park. • The statistic in this example is: • A) The 400 people contacted • B) All adult citizens in West Columbia • C) All registered voters with listed phone numbers in West Columbia • D) The percent of all adult citizens in West Columbia who favor improving the river-front park • E) The percent of the 400 people contacted who favor improving the river-front park

11. The City of West Columbia wants to survey its adult citizens . To do this they use the list of all registered voters who have listed phone numbers. They contact 400 of those people and find that 228 favor improving the river-front park. • The statistic in this example is: • A) The 400 people contacted • B) All adult citizens in West Columbia • C) All registered voters with listed phone numbers in West Columbia • D) The percent of all adult citizens in West Columbia who favor improving the river-front park • E) The percent of the 400 people contacted who favor improving the river-front park

12. The City of West Columbia wants to survey its adult citizens . To do this they use the list of all registered voters who have listed phone numbers. They contact 400 of those people and find that 228 favor improving the river-front park.

13. The City of West Columbia wants to survey its adult citizens . To do this they use the list of all registered voters who have listed phone numbers. They contact 400 of those people and find that 228 favor improving the river-front park.

14. The City of West Columbia wants to survey its adult citizens . To do this they use the list of all registered voters who have listed phone numbers. They contact 400 of those people and find that 228 favor improving the river-front park. 4) Increasing the sample size would: A) Decrease the bias in the statistic B) Decrease the variability in the statistic C) Increase the bias in the statistic D) Increase the variability in the statistic

15. A graduate educational psychology class decides to examine the effects of caffeine on the effectiveness of studying. They recruit 200 education majors at USC and randomly assign half of them to drink two caffeinated beverages during each of two two-hour study sessions on the history of the Crimean war. The other half is given only caffeine free drinks for the two hour study session. The two groups are then compared on their scores on a short quiz about the war. 6) This study can give evidence that caffeine causes a change in the effectiveness of studying because: A) The researchers assigned the treatment to the subjects. B) The researchers compared two groups. C) The researchers used a large number of students (200). D) The researchers used randomness.

16. 10) An industry dominated by several large firms tends to have many entry level positions with starting salaries around $40,000, and a few entry level positions at smaller firms with starting salaries around $30,000. If an industry trade group wants to make the industry sound like they pay well, they should report the: A) Mean of the salaries B) Median of the salaries C) IQR of the salaries D) Standard deviation of the salaries

17. Find the median for of the data set: • 3 19 8 15 12 • A) 3 D) 10 • B) 5.5 E) 12 • C) 8

18. 12) Consider the boxplot to the right. Which of the three groups (1, 2, or 3) is skewed to the left? A) 1 B) 2 C) 3

19. 11) The odds for a team to win their next game are of 4 to 3 against them winning. This means their estimated probability of it winning is: A) 1/4 ≈ 25.0% B) 1/3 ≈ 33.3% C) 3/7 ≈ 42.9% D) 4/7 ≈ 57.1% E) 3/4 ≈ 75.0%

20. 12) A raffle with 1,000 tickets has 1 grand prize worth $20,000, and 10 second prizes each worth $1,000. What is the chance of not winning any prize if you buy one of the tickets? A) 0.001 = 0.1% B) 0.011 = 1.1% C) 0.989 = 98.9% D) 0.99 = 99% E) 0.999 = 99.9%

21. 13) A raffle with 1,000 tickets has 1 grand prize worth $20,000, and 10 second prizes each worth $1,000. How much is a ticket “worth” (i.e., its expected value ) ? A) $2.00 B) $2.10 C) $3.00 D) $21.00 E) $30.00

24. 15) A 68% confidence interval for the proportion p is found to be 0.65±0.03. The 95% confidence interval would be: A) 0.65±0.01 D) 0.65±0.06 B) 0.65±0.015 E) 0.65±0.09 C) 0.65±0.03

25. 16) What is the chance that a student earned an A or B given that they reviewed over several days? A) 5% D) 40% B) 20% E) 80% C) 25%

26. 17) What percent of students received an A or B? A) d+e D) 48% B) d+f E) 140% C) e+g

27. 18) What is the probability of event B but not event A happening? A) 15%B) 30% C) 45% D) 70% E) 95%

31. 22) The correlations for the four graphs to the right are: -0.80, -0.52, -0.46, and 0.92. Which of them is -0.80? A) A B) B C) C D) D

32. 23) How much do we estimate the protein level of minnow larvae changes by when the level of metals goes up by one? A) -0.7146 D) 195.5888 B) -0.2912 E) 195.880 C) 0.5106

33. 24) What is the estimated protein level of the minnow larvae when the level of metals equals one? A) -0.7146 D) 195.5888 B) -0.2912 E) 195.880 C) 0.5106

34. 25) What percentage of the variation in protein in minnow larvae is explained by the concentration of metals in the water? A) 29.12% D) 195.5888% B) 51.06% E) 195.880% C) 71.46%