AP Statistics

Question 1

What is Cuss?

Answer 1

Center, unusual, shape, spread

Question 2

How to solve for IQR?

Answer 2

IQR=Q3-Q1

Question 3

How to solve for outliers?

Answer 3

Q3+1.5(IQR) and Q1-1.5(IQR)

Question 4

Resistant to outliers mean…

Answer 4

When the summary statistics is not changed very much when an outlier is removed.

Question 5

5# summary percentile

Answer 5

min-0%
Q1-25%
median-50%
Q3-75%
max-100%

Question 6

Formula for Z score

Answer 6

Z=x-mean/SD

Question 7

68% of values lie within…

Answer 7

1 SD of the mean

Question 8

90% of the values lie within…

Answer 8

1.645 SD of the mean

Question 9

95% of values lie within…

Answer 9

1.96 (about 2 SD) of the mean

Question 10

99.7% (almost all) of the values lie within…

Answer 10

3 SD of the mean

Question 11

Describe patterns

Answer 11

1. Identify variables and cases (each point represents a case)
2. Describe the shape of the relationship (linearity, clusters, outliers)
3. Describe the trend (up, down, positive, negative)
4. Describe the strength of the relationship
5. Dose the pattern generalize to other cases?
6. Are there plausible explanations for the pattern? is there a third or lurking variable that might be causing both?
   *5 and 6 may not always apply

Question 12

Predictor

Answer 12

explanatory variable, x-value

Question 13

Predicted

Answer 13

response variable, y-value

Question 14

Extrapolation

Answer 14

making a prediction when value of x falls outside the range of actual data

Question 15

Interpolation

Answer 15

making a prediction when value of x falls inside the range of actual data (this is safer)

Question 16

Predicted Error

Answer 16

The difference between the observed value of Y and the predicted value of Y or y hat

Question 17

How do you get residuals?

Answer 17

y-y hat

Question 18

How do you get Predicted Error?

Answer 18

y=mx+b

Question 19

What is Least Square Regression Line?

Answer 19

It’s the regression line for which the sum of squared errors (residuals) or SSE is as small as possible, SSE= (y-y hat) ^2

Question 20

How do you interpret r^2?

Answer 20

the __% change in y explained by change in x (+ context)

Question 21

How to calculate r^2?

Answer 21

• SST=Sum of Square Total SSE= sum of Square error
  r^2= SST-SSE/SST
  On calculator it is LinReg

Question 22

How to make a Residual Plot?

Answer 22

A scatter plot of residuals, y-y hat versed predictor values, X.
1. Highlight L3 and type in the Regression Lin
2. Then Highlight L4 and type L2-L3
3. Graph (L1,L4)

Question 23

How to calculate Exponential Relationship?

Answer 23

L1-x
L2-y
L3-ln(L2)

Question 24

Population gose with…

Answer 24

parameter

Question 25

Sample gose with...

Answer 25

statistic

Question 26

Steps in choosing a Simple Random Sample

Answer 26

1. Start with a list of all units in the population 2. Number the units in the list 3. Use a random number table of generator to chose units from the numbered list

Question 27

Steps in chosing a Stratafied Random Sample

Answer 27

1. Divide unites into strata (subgroups 2. Take a Simple Random Sample from each subgroup

Question 28

Steps for Cluster Samples

Answer 28

1. Create a number list of all cluster in the population 2. Take Simple Random Samples of clusters 3. Obtain data on each individual in each cluster in your Simple Random Sample

Question 29

Steps in Systematic Sample

Answer 29

1. Take total units in the population and divide by number of units you want in the sample to get the kth 2. Select a random start, then every kth number after to be in sample

Question 30

What is a Lurking Variable?

Answer 30

It's a variable that lies in the background and may or may not be apparent at the outset but could explain the pattern

Question 31

Probability is between...

Answer 31

0 and 1 (0% and 100%)

Question 32

What is Observed Data?

Answer 32

Long-run relative frequencies (experimental probability)

Question 33

What is Symmetry (probability)?

Answer 33

Equally likely outcomes (theoretical probability)

Question 34

What is Subjective (probability)?

Answer 34

Estimates, make a judgment

Question 35

What are the steps in a Simulation that uses random digits?

Answer 35

1. Assumptions- __% is the true percentage, and ______ are independent 2. Model- 0-1 are ___ and 2-9 are _____ 3. Repetition- randint(a,b,c) repeats are okay, real number of ________ 4. Conclusion- # of times _____/ total simulation runs

Question 36

U for addition rule means...

Answer 36

or

Question 37

n for addition rule means...

Answer 37

and