Term
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Definition
| Observations we objectively make of our environment |
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Term
| Why do we use statistical analysis? |
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Definition
| Dram conclusions, better understand the source of the data, data reduction, inference, ID relationships and associations, |
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Term
| What is a discrete random variable? |
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Definition
| Has non-measurable gaps between values (ex: cow shit scores) |
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Term
| What is a continuous random variable? |
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Definition
| any value number is possible |
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Term
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Definition
| Pregnant or not, live or dead, etc (mutually exclusive categories) |
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Term
| What is an ordinal scale? |
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Definition
| Ranked categories (cow shit, beef quality grades, etc.) |
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Term
| What is an interval scale? |
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Definition
| Quantitative, but no true zero exists (his example was temp) |
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Term
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Definition
| "Highest level of measurement" - has a true zero |
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Term
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Definition
| A well-defined collection of entities - may be finite or infinite |
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Term
| What is the sample population? |
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Definition
| A representative sample of the entire population |
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Term
| What is a descriptive statistic? |
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Definition
| A single calculated number that conveys important info about the data from which is was calculated |
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Term
| The average human being has one breast and one testicle |
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Definition
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Term
| What is an ordered array? |
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Definition
| The simplest form of data organization used to calc min, max, and range |
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Term
| What is an advantage of a stem and leaf plot? |
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Definition
| It conserves information about individual measurements |
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Term
| What are 3 measures of central tendency? |
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Definition
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Term
| Why does snoop dog carry an umbrella? |
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Definition
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Term
| What's the difference between mew and bar x? |
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Definition
| mew = pop mean, bar x = sample mean |
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Term
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Definition
| The variation in a data set |
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Term
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Definition
| Subtract the mean from every value (residual), square the results, sum them, and divide by n-1 (degrees of freedom) |
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Term
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Definition
| Subtract the mean from every value (residual), square the results, sum them, and divide by N (degrees of freedom) |
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Term
| Explain degrees of freedom |
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Definition
| The deviations from the mean will always sum to zero. If we know the values of (n-1) of the observations and the value of the mean, we can, using simple algebra, determine the value of the unknown observation. Therefore, all of the observations except for 1 (n-1) are ‘free to vary.’ |
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Term
| Within how many St dev do most of your data lie? |
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Definition
| Almost all data of any data set will lie with 3 STD of either side of the mean |
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Term
| How do you calculate sample variance? Pop variance? |
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Definition
| square root of s^2, square root of that funny looking o |
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Term
| What is the interquartile range? |
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Definition
| Q3-Q1 - the difference between the 3rd and 1st quartiles |
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Term
| What 2 things do descriptive stats tell you? |
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Definition
| Central tendency and dispersion |
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Term
| What's the eqn for probability? |
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Definition
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Term
| What's the eqn for relative frequency probability? |
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Definition
| P(E)=m/n - this works if there is a large sample |
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Term
| What are 3 properties of the Probability Theory as stated by Kolmogorov? |
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Definition
1.P(any event) must be a non-negative number
2.Sum of mut excl events all add to 1
3.Prob of any 2 mut excl events is equal to the sum of their probabilities |
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Term
| What is conditional probability? |
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Definition
The probability of an event, given certain circumstances (what is the prob a cow has had bloat 5 times, given that animal is male?)
P(C | M)? |
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Term
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Definition
| Probability of an event given 2 or more characteristics (what is the prob a cow has had bloat 5 times and that animal is male?) |
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Term
| What is the multiplication rule? |
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Definition
We can compute a joint probability as the product of an appropriate unconditional probability and an appropriate conditional probability, which is called the Multiplication Rule
P(M ∩ C) = P(M)*P(C | M) |
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Term
| What is the addition rule? |
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Definition
Given two events A and B, the probability that event A, or event B, or both occur is equal to the probability that event A occurs, plus the probability that event B occurs, minus the probability that the events occur simultaneously
P(M∪ C) = P(M) + P(C) – P(M ∩ C)
P(A or B) = P(A) + P(B) when A and B are mutually exclusive events |
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Term
| How do you calculate prob of independent events? |
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Definition
Events are considered independent if Event B occurring has no effect on the probability of Event A occurring. This is not the same concept as mutually exclusive.
P(A|B)=P(A) |
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Term
| What is the multiplication rule or independent events? |
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Definition
If two events are independent, the probability of their joint occurrence is equal to the product of the probabilities of the individual occurrences
P(A∪B) = P(B)*P(A); P(A) ≠ 0 and P(B) ≠ 0 |
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Term
P(A|B) = P(A)
P(B|A) = P(B)
P(A∩B) = P(A)*P(B)
These statements are true for what type of events? |
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Definition
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Term
| What is a false positive? |
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Definition
| a test indicates a positive result when the true result is negative |
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Term
| What is a false negative? |
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Definition
| a test indicates a negative result when the true result is positive |
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Term
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Definition
| I skipped it because he skipped it. I think. It's really long and stupid. |
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Term
| What does a nosy jalapeno do? |
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Definition
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Term
| Name 3 qualities of probabilities of discrete, random variables |
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Definition
All probabilities are positive
All probabilities are less than 1
0 ≤ P(X = x) ≤ 1
All exhaustive probabilities sum to 1
∑ P(X = x) = 1 |
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Term
| How do you calculate cumulative probability? |
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Definition
Cumulative Probability is obtained by successively adding the probabilities, P(X = x), given in the last column of the probability distribution
Written as P(X ≤ xi), gives probability that X is less than or equal to a specified value, xi |
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Term
| Tell me about Bernoulli trials |
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Definition
A Bernoulli Trial is any process or event that:
Results in one of two possible, mutually exclusive, outcomes.
The probability of a success, p, remains constant from trial to trial. The probability of a failure, q, is 1 – p.
The trials are independent; the outcome of any particular trial is not affected by the outcome of any other trial. |
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Term
| What is the multiplication rule? |
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Definition
| pqppq = p3q2 via multiplication rule |
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Term
| What is the equation for factorial? |
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Definition
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Term
| What are the parameters of binomial distributions? |
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Definition
| n and p are the only 2 parameters of binomial distributions |
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Term
| What is a continuous random variable? |
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Definition
| A Continuous Random Variable is one that can assume any value within a specific interval of values assumed by the variable. eg: there are an infinite number of values of the variable. |
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Term
| What is the most important distribution in stats? |
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Definition
| The normal one! AKA Gaussian dist |
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Term
| Mean and standard deviation measure what? |
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Definition
| The parameters mean and standard deviation can be thought of as measures of central tendency and dispersion |
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Term
| What are characteristics of the normal distribution? |
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Definition
Symmetrical about the mean
Mean = median = mode
Total AUC about the x-axis is one square unit. – 50% of the area is to the left of the mean and 50% is to the right of the mean
If we erect perpendiculars a distance of 1 SD from the mean in both directions, the area ~ 68% of the total area (see figure previous page)
Distribution determined by the parameters mew and funny o |
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Term
| How do you calculate z score? |
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Definition
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Term
| 21.What’s brown and sticky? |
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Definition
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Term
| What is the difference between joint and conditional probabilities? |
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Definition
joint - the events are independent
P(A and B)=P(A)*P(B)
conditional - the events are dependent
P(A and B)=P(A)*P(B|A) |
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