The following is a list of suggestions and questions to review for Exam II.

1. Know how to find the mean and median from a list of numbers.
2. What are measures for the 'center' of a distribution?
3. What are measures for the 'variability' of a distribution?
4. Give a stemplot of three hypothetical datasets (you can make up the numbers) consisting of 10 datapoints with each having one of the following characteristics: skew left, symmetric, and skew right.
5. Know how to construct a stemplot and be able to identify potential outliers using it.
6. Be able to calculate percentiles of a Normal distribution using standardized scores and Table 8.1.
7. Approximately what proportion of measurements from a bell shaped distribution are within 1 standard deviation of the mean? 2 standard deviations? 3 standard deviations?
8. Understand the role of natural variability in statistical relationships.
9. Know what statistical significance means (and keep in mind the warnings about it).
10. Correlation (pictures are helpful ways to illustrate ideas)
    1. What does it measure?
    2. How is it affected by outliers?
    3. What does strong correlation look like graphically?
    4. What numerical values of the correlation coefficient indicate strong correlation?
    5. What does weak correlation look like graphically?
    6. What numerical values of the correlation coefficient indicate weak correlation?
    7. How are positive and negative correlation different?
    8. Give numerical and graphical examples that indicate/show positive and negative correlation.
    9. Understand how correlation (or lack thereof) can be misleading.
    10. Does correlation imply causation?
11. Use the scatterplot when answering the two questions that follow.
    
    Suppose the relationship between fuel efficiency on the highway and fuel efficiency in the city for two-seater sports cars can be modeled using the following regression equation: y= 9.14 + 0.856 x where y is fuel efficiency on the highway and x is fuel efficiency in the city.
    1. If your two-seater sports car gets 28 miles per gallon in the city, what is the predicted mileage for the highway?
    2. What is the predicted highway mileage for 0 mpg in the city? Why does this result not make sense and why is it inadvisable to make a prediction for 0 mpg in the city given our data?
12. For each of the following pairs of variables, give one or two reasons why they may be related and explain your choice(s):
    1. In Sitka: Daily sales of artwork and daily high temperature
    2. Cell phone sales and internet usage
    3. Number of students and number of meals prepared in the cafeteria
    4. age and income
    5. average annual rainfall and #of wildfires per year
    6. Amount of money gained via fundraising by a political candidate and the percentage of the vote that goes the the same candidate.
13. Understand why it may be important to use rates instead of raw counts when comparing data from different populations.
14. If you have a relative risk of 1.5 of cancer due to family history, what is your increased risk? If you have an increased risk of 30% for a certain disease, what is your relative risk?
15. How can statistics about risk be misleading?
16. Recall that there are two interpretations of probability: relative frequency and personal probability. Which interpretation applies to this statement: "The probability that I will pass this exam is 75%"? Explain.
17. Explain which of the following more closely describes what it means to say that the probability of a tossed coin landing with heads up is 1/2:
    Explanation 1: After more and more tosses, the fraction of heads will get closer and closer to 1/2.
    Explanation 2:The number of heads will always be about half the number of tosses.
18. Give one example of how each of the following concepts has had or might have unwanted effect on a decision or action in your daily life: (if necessary refer to Chapter 16 for explanation of terms)
    1. Conservatism
    2. Optimism
    3. Forgotten base rates
    4. Availability
19. Suppose you play the roulette wheel on your next trip to Vegas. If you place your bet on red three times in a row and lose each time with the winner being black. Which of the following scenarios best describes your situation?
    1. You should place your next bet on red because it is very unlikely for red to lose four times in a row.
    2. You should place your next bet on black because clearly there is something going on with the wheel.
    3. It does not matter whether you stay with red or go with black.
20. Suppose you go to your doctor for a routine examination, without any complaints of problems. A blood test reveals that you have tested positive for a certain deadly disease. What should you ask your doctor in order to assess how worried you should be?
21. Suppose two sisters are reunited after not seeing each other since they were 3 years old. They are amazed to find out that they are both married to men named James and that they each have a daughter named Jennifer. Explain why this is not so amazing.