Jeopardy. Ben is too lazy to think of fancy titles

Transcription

1 Jeopardy Ben is too lazy to think of fancy titles

2 Rules I will randomly move people into groups of 2 or 3. I will select a random group to choose a question. Then I will allow some time for all the groups to attempt the question. First person to get the answer gets the points for the question. I will discuss the answers after every question. There are some questions not related to stats (last 2 columns), but after choosing a nonstats question the next question must be a stats question. Ben reserves all rights to add info to or change the questions, and give hints.

3 Random sampling Chapter 1 stuff Totally not stats Stats people

4 Random sampling 100 During Fall 2016, the STAT 1030 class has 22 sections and 28 students in each section. A TA randomly selects 3 students from each section to participate in a survey about study habits. This form of sampling is known as (simple random / stratified / cluster ) sampling. Stratified sampling. Each section is a strata from which a portion is drawn.

5 Random sampling 200 During Fall 2016, the STAT 1030 class has 22 sections and 28 students in each section. A TA wants to understand study habits of students in this class, so he s everyone in the class and asks them to complete a survey about study habits. Students who choose to complete the survey get 0.5% extra credit. What sampling scheme is this? Is it random? Voluntary response sampling. Since students are not required to complete the survey, the sample may be biased towards students who value the 0.5% more than the time taken to complete the survey.

6 Random sampling 300 During Fall 2016, the STAT 1030 class has 22 sections and 28 students in each section, for 616 students in total. A TA wants to understand the study habits of students in the class, and so wants to randomly select 6 students to participate in the survey. Use the random numbers below to select which students are selected. (Use labels 1...) The labels selected are: 394, 29 (029), 35 (035), 39 (039), 230, and (r)

7 Random sampling 400 During Fall 2016, the STAT 1030 class has 22 sections and 28 students in each section, for 616 students in total. Further suppose there are exactly equal number (308) of males and females. A TA wants to randomly select 6 students in the class for a survey. Using stratified sampling, use the random numbers below to select a sample that is representative with respect to sex. (Use labels , select males first then females) The labels selected are: 120, 304, 012 for males, and 213, 301, 156 for females (r) (r)

8 Chapter 1 stuff 100 Is course number (e.g. 1030) a quantitative or categorical variable? Categorical. The number has no other function but serve as an identifier.

9 Chapter 1 stuff 200 Is this distribution skewed to the left or right? Skewed to the right. The longer tail is on the right side.

10 Chapter 1 stuff 300 Suppose the mean economic growth rate of the US is smaller than the 1 st quartile of all economic growth rates. Are economic growth rates symmetric, or skewed? If skewed, to the left or right? Skewed left. The question states that the mean is smaller than 75% of data, which is much smaller than the median. So there must be outliers far out to the left that pull the mean downwards.

11 Chapter 1 stuff 400 Ben s rice consumption per month has a mean of 45lbs and SD of 2lbs. What can be said about the % of times Ben ate between 40 and 50 lbs of rice, using Chebyshev s inequality? 40 and 50 lbs of rice is lbs, and 5 lbs is 2.5 * 2 lbs = 2.5 SD s away from the mean. By Chebyshev s, the proportion is at least 1 (1/2.5)^2 = 0.84 = 84% of times Ben ate between 40 and 50 lbs of rice.

12 Totally not stats 100 This building is featured on the UI logo. It was used as a University administrative building before being converted to a museum. Iowa Old Capitol.

13 Totally not stats 200 This body of water is a minute drive from campus, and shares its name with one of the buildings on the Pentacrest. Lake Macbride.

14 Totally not stats 300 You look at a cat, and it stares back at you. After some time, you realize it is noticeably cuter, because its pupils are dilated. At this point, you should probably stop, because it is about to Cat s pupils dilate in response to fear, defensiveness, or playfulness. But chances are it is planning to jump on you.

15 Totally not stats 400 Interiors of casinos lack two very important characteristics that most other buildings have. One is a very commonplace household appliance, and the other is a common construct found in almost every other building. The omission of these is used to entice the gambler to play more. What are these two characteristics? Clocks and windows. These are so that the gambler isn t immediately aware how much time has passed since playing, so that the gambler will continue to play.

16 Stats people 100 Which country is Ben from? Ben is from Malaysia.

17 Stats people 200 A picture of Hank is featured on Matt s homepage. What was Hank s relationship with Matt? Hank was Matt s dog.

18 Stats people 300 A quote from Matt: If you want to feel loved,. Get a dog.

19 Stats people 400 What does Ben think is a key ingredient in Malaysian chicken curry? Coconut milk.