## Test your basic knowledge |

# AP Statistics Vocab

**Instructions:**

- Answer 50 questions in 15 minutes.
- If you are not ready to take this test, you can study here.
- Match each statement with the correct term.
- Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

**1. A positive ____ or association means that - in general - as one variable increases - so does the other; when increases in one variable generally correspond to decreases in the other - the association is negative**

**2. The sum of squared deviations from the mean - divided by the count minus one**

**3. When groups of experimental units are similar - it is a good idea to gather them together into these**

**4. This of sample size n is one in which each set of n elements in the population has an equal chance of selection**

**5. Adding a constant to each data value adds the same constant to the mean - the median - and the quartiles - but does not change the standard deviation or IQR**

**6. The best defense against bias - in which each individual is given a fair - random chance of selection**

**7. The ____ we care about most is straight**

**8. A point that does not fit the overall pattern seen in the scatterplot**

**9. A representative subset of a population - examined in hope of learning about the population**

**10. The specific values that the experimenter chooses for a factor**

**11. The most basic situation in a simulation in which something happens at random**

**12. To describe this aspect of a distribution - look for single vs. multiple modes - and symmetry vs. skewness**

**13. When an observed difference is too large for us to believe that is is likely to have occurred naturally**

**14. A numerically valued attribute of a model for a population**

**15. A variable other than x and y that simultaneously affects both variables - accounting for the correlation between the two**

**16. Data points whose x-values are far from the mean of x are said to exert ____ on a linear model; with high enough ____ - residuals can appear to be deceptively small**

**17. Anything in a survey design that influences response**

**18. The differences between data values and the corresponding values predicted by the regression model; ____ = observed value - predicted value**

**19. Doing this is equivalent to changing its units**

**20. To be valid - an experiment must assign experimental units to treatment groups at random**

**21. A distribution is this if the two halves on either side of the center look approximately like mirror images of each other**

**22. Control - randomize - replicate - block**

**23. Consists of the minimum and maximum - the quartiles Q1 and Q3 - and the median**

**24. An individual result of a component of a simulation**

**25. Ideally tells who was measured - what was measured - how the data were collected - where the data were collected - and when and why the study was performed**

**26. A scatterplot shows an association that is this if there is little scatter around the underlying relationship**

**27. An equation of the form y-hat = b0 + b1x**

**28. The difference between the lowest and highest values in a data set**

**29. The square root of the variance**

**30. Summarized with the standard deviation - interquartile range - and range**

**31. Values of this record the results of each trial with respect to what we were interested in**

**32. The linear equation y-hat = b0 + b1x that satisfies the least squares criterion**

**33. A sample is this if the statistics computed from it accurately reflect the corresponding population parameters**

**34. Gives a value in 'y-units per x-unit'; changes of one unit in x are associated with changes of b1 units in predicted values of y**

**35. Displays the 5-number summary as a central box with whiskers that extend to the non-outlying data values**

**36. These are hard to generate - but several websites offer an unlimited supply of equally likely random values**

**37. A variable that is not explicitly part of a model but affects the way the variables in the model appear to be related**

**38. Numerically valued attribute of a model**

**39. A numerical summary of how tightly the values are clustered around the 'center'**

**40. Useful family of models for unimodal - symmetric distributions**

**41. An equation or formula that simplifies and represents reality**

**42. A value that attempts the impossible by summarizing the entire distribution with a single number - a 'typical' value**

**43. Shows quantitative data values in a way that sketches the distribution of the data**

**44. The lower of this is the value with a quarter of the data below it; the upper of this has a quarter of the data above it**

**45. This - b0 - gives a starting value in y-units; it's the y-hat-value when x is 0**

**46. Summarized with the mean or the median**

**47. An event is this if we know what outcomes could happen - but not which particular values will happen**

**48. This corresponding to a z-score gives the percentage of values in a standard normal distribution found at that z-score or below**

**49. Lists the categories in a categorical variable and gives the count or percentage of observations for each category**

**50. In a normal model - about 68% of values fall within 1 standard deviation of the mean - about 95% fall within 2 standard deviations of the mean - and about 99.7% fall within 3 standard deviations of the mean**