Show:
Normal Distribution (but what is normal, anyways?)
Statistically Speaking
In All Probability
What Frequency Are You Using?
Random Things Like Sloths
100
What are the quartiles in this data? 1 2 3 4 5 6
2, 3.5, 5
100
What is the difference between descriptive statistics and inferential statistics?
Descriptive stats describe a sample. Inferential stats make inferences about a POPULATION.
100
What is the probability that you will draw a heart OR a spade from a deck of cards?
13 / 52 + 13 / 52 = 26 / 52 = 50% (or .5) That is the ADDITIVE RULE
100
How can you make a histogram if you have 100 different data points to plot? Isn't that a LOT of bars?
Use frequency intervals. Group the data together into intervals.
100
Ok, 2 parts: 1. What does BEDMAS mean? 2. If you are calculating a sum (SIGMA), should we assume there are brackets around the things you are summing?
1. Order of operations - brackets, exponents, division and multiplication, addition and subtraction. Do math in an equation in this order. 2. Yes. If you are expanding a sigma to add a bunch of stuff together, assume you can bracket those sums as one part of the calculation.
200
In a normal distribution, what percent of scores lie within 1 SD of the mean?
34.13 + 34.13 = 68.26%
200
What is the difference between stats and parameters?
Stats summarize samples. Parameters summarize populations.
200
You have a bag full of M&Ms: 10 red, 10 green, and 10 yellow. What is the probability of reaching in and randomly drawing a red, putting it back, and then drawing a green?
10 / 30 x 10 / 30 = 100 / 900 = 1/9 That is the MULTIPLICATIVE LAW
200
What 5 numbers are needed to make a box and whisker plot?
Minimum, Maximum, Quartile 1, Quartile 2 (Median), Quartile 3.
200
What calculation would you do if you want to compare your test result with a friend's test result, but your tests are out of different amounts, and you are in different classes?
Individual z score. Use it when you compare individual scores which can be compared to their own samples having their own means and SDs. score - sample mean / sample SD
300
What kind of skew is it if the mountain part is on the left, and the tail on the right?
Positive skew
300
What is the difference between quantitative and categorical data?
Quantitative data measure something numerical along a scale of measurement. Categorical data count the number of things in each category.
300
First team to show me the Probability Tip Sheet wins the points!
Please print out all the Tip Sheets, and review them together so you can compare and contrast how to do each type of calculation!!
300
Which do you like better, giraffes or transparent fish?
CLEARLY, transparent fish.
300
What does N(100, 25) mean?
You have a normal distribution with a mean of 100 and a variance of 225) You could also say you have an SD of 15.
400
What are the means and SDs of the 3 following distributions: Normal IQ z scores
Normal: mean of 0, SD of 1 IQ: mean of 100, SD of 15 z scores: mean of 0, SD of 1
400
Of the four types of scales (nominal, ordinal, interval, and ratio), what scale is height?
Ratio - there is a true zero (lack of any height), and there is an equal distance between heights (someone 6 feet tall is twice as tall as someone 3 feet tall).
400
What is the probability that a randomly selected person's z score from a standardized test will be greater than 1.96 or less than -1.96?
5%. Those are the critical values of the z distribution. For the t tests, you will need the critical value table based on sample size (df)
400
It doesn't have to do with frequency. But, here it is: If you are testing to see if a water additive can successfully increase the life expectancy of fish in a fish hatchery, and you find that the additive DID make a difference but really, it was error, as the additive has subsequently shown to have no effects, what KIND of error was it?
Type I - you found an effect, when in reality there was none. AKA False Positive
400
You have a score of 130 on a test which has a mean of 100 and SD 20. You calculate your z as 1.5. How often would we find scores this high, knowing that when we looked up the value on the z chart (areas under the curve) shows as .0668?
Remember that the z chart doesn't show critical values - it shows percentages of the distribution. If 1.5 corresponds to .0668, we expect to find a rate this high, or higher, 6.68% of the time. GOOD FOR YOU!!
500
What calculation do we do when we want to find out the average difference of each score from its mean (by summing the squares and dividing by the degrees of freedom within a distribution?
Variance (or standard deviation if you take the square root of that)
500
If you are studying the effects of alcohol on driving, which is the dependent and which is the independent variable?
Alcohol consumption is the independent variable. Driving is the dependent variable, because it depends on how much alcohol was consumed. Please don't try this experiment at home.
500
What was the hardest thing you learned in this class so far, and what helped you to master it?
No points if you just say you didn't master it. Points if you share a strategy or tip that worked well for you!
500
The central limit theorem states that even if we have an irregularly shaped population, the sampling distribution of the means taken from that population will be shaped like this ______________, and you will likely need a sample size of _______ to see this shape start forming
Normal. Size of 30. In your research, try to have a sample this size whenever you can when dealing with irregularly shaped distributions (such as test marks, which rarely average 50%)
500
Sorry - there have been no sloths. FREE POINTS just for picking this, though!
(We can't ALWAYS have sloths in our activities)