Study Guide 1 (due Mon. 10/1)
StudyGuide1Answers-SLStats (click to download the worked solutions)
Study Guide 2 (due Wed. 10/3)
Study Guide 3 (due Thurs. 10/4)
Univariate Study Guide 3 (Questions)
The vocabulary words are also below, with examples and links to other websites that might explain them better.
|1. Population||A collection of individuals about which we want to draw conclusions||e.g. all Americans, all IDEA Donna seniors|
|2. Census||The collection of information from the whole population||e.g. Census 2010, the April ACT|
|3. Sample||A subset of the population. (It is important to choose a sample at random to avoid biased results.)||e.g. every third house, 20% of each homeroom|
|4. Bias||Misleading data, usually because a sample was not truly random||e.g. only counting seniors who took the ACT in December (might have a lower score than the overall average because they are retaking)|
|5. Random Sampling||Choosing a subset of the population at random to avoid bias||e.g. setting quotas of each type of person, not just asking friends and family|
|6. Survey||Collection of information from a sample||e.g. CNN polls asking 1,000 Americans who their preferred candidate is.|
|7. Data (singular: datum)||Information about individuals in a population||e.g. I asked each person in 3rd period for one datum: his or her highest ACT score. When I put them in a list, I had data for 3rd period.|
|8. Parameter||A numerical quantity measuring some aspect of a population. (As statistics are to samples, parameters are to populations.)||e.g. I estimated the whole grade’s average ACT score (parameter) by looking at my homeroom’s average (statistic).|
|9. Statistic||A quantity calculated from data gathered from a sample. (Usually used to estimate a variable for the population)||e.g. mean ACT score, range of student heights in a homeroom|
|10. Distribution||The pattern of variation of data.
|The distribution for SL’s Vectors Test is negatively skewed because the data looks flattened on the left of the mode.|
|11. Outliers||Data much larger or much smaller than the general body of data. Include outliers unless they are a result of error.||Actual outlier: A police officer is measuring the speeds on 83. Most are going 70mph – then someone idles by at 45mph.
Error outlier: I accidentally stepped on the scale while weighing my cat.
|12. Discrete Variable||A variable that takes exact number values. (Usually a result of counting)||e.g. number of people in a room, shoe size, date, number of rooms in a house|
|13. Continuous Variable||A variable that takes number values within a certain range. (Usually a result of measuring)||e.g. height in cm, weight, temperature|
|14. Frequency||The number of individuals in a survey who share a characteristic OR the number of times an event occurs||e.g. 6 people were late to 3rd period yesterday; 69,456,897 people voted for Obama in 2008|