Chapters 1-3
Pie Charts and Bar Graphs display the distribution of what type of variable?
Categorical Variables
The part of the population that we would like to study a phenomena with regards to is called this.
The population of interest.
A news anchor claims that we should not question the science. What is the problem with this statement?
Science is by definition that which can be questioned.
You select a card at random from a well shuffled deck of cards. What is the probability of getting either a heart or an ace?
16/52 = 4/13
This is used to adjust what p-value we would take to accept or reject the null hypothesis.
Alpha level
Median Income in America is an example of what type of skew distribution?
Skew Right
A scatter plot compares what types of data.
Quantitative.
A YouTube poll from a political channel finds overwhelming support for their viewpoints. This is an example of what?
Selection Bias/Voluntary Response Bias
You flip 5 coins. What are the odds of getting exactly 3 heads?
n = 5, k = 3, P(n = k) = n!/(k!(n - k)!) * (1/2)^3 * (1 - 1/2)^(5 - 3) = 0.3125
The natural variability that arises from the random aspects necessary for generalization out to the population of interest is called:
Sampling Variability.
What percentage of observations fall within 2 standard deviations of the mean in a normally distributed data set?
95%
For our questionnaires preparatory to our final projects, we used this method of sampling.
Stratified Random Sampling.
When should the alpha-level for a statistical study be decided upon?
Before the study is conducted.
10/36 = 5/18
An incorrectly calibrated drug test falsely identifies an individual as having a communicable disease they do not actually have. This is an example of this type of error.
Type 1 (False Positive)
A correlation coefficient close to -1 implies this
A strong negative linear relationship between the input and output variables.
When a participant in a study purposely falsifies results to spite the person/people conducting the study, this is called what.
Trolling.
You notice that the mean is used in a statistical study instead of the median. What manipulation is the mean susceptible to?
The mean is susceptible to outliers which may not be representative of the dataset at large. Ex: Income
64/100 = 16/25
A quality control machine at a food manufacturing plant incorrectly allows a diseased potato to be turned into potato chips. This is an example of this type of error.
Type 2 (False Negative)
Statistical Regression is inaccurate for predictions which are outside of your typical input data, called this.
Extrapolation
Random allocation to differing treatments allows for this statistical inference.
Causation
A statistical study is found to be statistically significant. However, you learn that the statistician has repeated the study well over a dozen times, with increasing sample sizes each time. What type error has likely occurred?
Type 1 Error (False Positive)
A Talented Bottle Flipper can land a water bottle flip approximately 25% percent of the time. He flips the bottle for his friends 5 times. What are the odds of him making it at least 2 times?
Approximately 0.3671875
There is a very high correlation coefficient when comparing the Burglary Rate in Kansas and the distance between Neptune and Earth. This is an example of the following.
"Spurious Correlation", or "Correlation is not Causation."