Experiments / Study
Probability
Z Test / Interval
T Test / Interval
Random
100
A teacher is carrying out an observational study. She interviews the first 50 students that walk into the building.
What kind of bias is present?
Convenience bias
100
What does BINS stand for?
B:Binary
I: Independent
N: Number of trials
P: Same probability
100
What is the difference between a z test and z interval?
A z test is given the population proportion while a z interval estimates the population proportion.
100
For the Large Counts condition in a Chi-Squared distribution, what is the minimum expected count?
At least 5
100
What is the 5-Number Summary?
Minimum value, Q1, median, Q3, and maximum value.
200
Researchers took a random sample of people and examined their social media habits. Each person was classified as either a light, moderate, or heavy social media user. The researchers looked at which groups tended to be happier. Are there any treatments given in this study?
None because this is an observational study.
200
What is a simulation device?
Ex: random digit table, random number generator, dice, deck of cards, or coins.
200
Determine if the conditions are met to calculate a significance test.
A college president says “99% of alumni support my firing of Coach Boggs.” You contact an SRS of 200 of the 15,000 alumni to test the hypothesis Ho: p = 0.99.
Conditions NOT met.
Large Counts: np = (200)(.99) = 198, n(1-p) = (200)(0.01) = 2
Expected counts NOT all at least 10. Sampling distributions of p̂ is NOT approx. normal
200
What is the point estimate? Interval: (79.9345, 83.0284)
81.4815
200
What is this type of graph?
Segmented Bar Graph
300
Name one advantage and disadvantage to using a systematic sampling method.
Ad: Simple to carry out
Dis: Need an ordered list of the population
300
What is the difference between continuous and discrete variables?
Continuous variables can be decimals, but discrete variables cannot.
300
What is the z* value for a 92.45% confidence interval?
1.777
300
If n<30, what must you do to satisfy the Approx. Normal Condition?
Graph the data and show there is no strong skew or outliers.
300
What percent of the data is within 1 standard deviation of the mean on a normal curve?
68%
400
_______ - examine existing data for a sample of individuals.
_______ - track individuals into the future.
_______ - treatment assigned; shows causation
Retrospective
Prospective
Experiment
400
What is the Law of Large Numbers?
The long-run relative frequency of repeated independent events gets closer and closer to the true relative frequency as the number of trials increases.
400
Any Miami Heat fan or archival knows the team’s very large “SHAQilles heel”- the free-throw shooting of Shaquille O’Neal. Over his NBA career, Shaq has made 53.3% of his free throws. One year, Shaq worked during the off-season with an assistant coach on his free-throw technique. The next season, Shaq made 26 out of 39 free throws. Interpret the p-value.
Assuming the true population proportion of free throws Shaq makes is 0.533, there is a 0.0475 probability of getting a sample proportion of 0.6667 or more.
400
What kind of test is this:
Use the sample data for the 100 customers to conduct a statistical test to determine if the waiting times at the new branch office are inconsistent with the acceptable for the waiting time categories.
X2 for Goodness of Fit
400
What are the conditions for inference testing/interval for slope?
Linear, Independent, Normal, Equal SD, and Random.
500
Define power
Power refers to the likelihood of a hypothesis test detecting a true effect if there is one
500
What is the interpretation of an expected value?
If many, many units, are randomly selected, the average x-variable is about #.
500
What is the effect size?
The difference between the null hypothesis value and the actual value of the population parameter.
500
What kind of test is this?
A random sample of 30 adults were selected. Each adult reported the number of pieces of junk mail they received in their mailbox at home that day as well as the number of junk emails they received in their inbox that day. A researcher would like to know if adults receive significantly more junk email than junk mail in their mailbox.
One-sample matched-pairs t test for μD
500
What is the Simpson’s Paradox?
When averages are taken across different groups, they can appear to contradict the overall averages.