Organizing Data
Miscellaneous
Producing Data & Experiments
Probability & Distributions
Inference & Tests
100
This measure of center is more resistant to outliers than the mean.
What is the median?
100
What percent of data falls within two standard deviations of a normal distribution?
Approximately 95%
100
This phrase is used to describe an observed effect so large that it would rarely occur by chance.
What is statistically significant?
100
This type of random variable requires a fixed number of trials.
What is a binomial random variable?
100
The type of significance test used for the mean of a single population when the standard deviation of the population is unknown.
What is a T test (or T procedure)?
200
To calculate, subtract the mean of the distribution from the observed x, then divide by the standard deviation.
What is the z-score (or standardized value)?
200
What does this test? P(B|A)=P(B)
Independence
200
What is the difference between an observational study and an experimental study?
Experimental study imposes treatment, observational study does not.
200
The type of variable where the probability distribution assigns probability as the area under the density curve above a specific interval.
What is a continuous random variable?
200
The formula to calculate the one-proportion z statistic.
What is z = (p hat minus p sub o) divided by (square root of [(p - p sub o)/n]) ?
300
This rule helps to determine if data is normally distributed by checking the number of observations within each interval.
What is the 68-95-99.7 rule?
300
This is an example of what kind of distribution?
Right skew
300
This experimental design involves the random assignment of units to treatments which are carried out separately within each group of units known to be similar in some way that is expected to affect the responses.
What is block design?
300
Events that have no outcomes in common and can never occur simultaneously, for which the addition rule is used.
What are disjoint events (or mutually exclusive events)?
300
The three conditions to be verified for inference about a proportion.
What are 1. SRS
2. The population size be greater than or equal to 10n and
3. n times p hat & n times (1 - p hat) be greater than or equal to 10?
400
The square of the standard deviation.
What is the variance?
400
The time to complete a standardized exam is approximately normal with a mean of 70 minutes and a standard deviation of 10 minutes. How much time should be given to complete the exam so that 99% of the students will complete the exam in the time given?
93.3 minutes
400
The 3 basic principles of experimental design.
What are control, randomize, and replicate?
400
The condition involving the population size that must be satisfied to use sigma divided by the square root of n as the standard deviation of a sampling distribution.
What is 'the population is at least 10 times the sample size'?
400
It has been suggested that drinking red wine in moderation may protect against heart attacks. This is because red wind contains polyphenols which act on blood cholesterol. To see if moderate red wine consumption increases the average blood level of polyphenols, a group of nine randomly selected healthy men were assigned to drink half a bottle of red wine daily for two weeks. The percent change in their blood polyphenol levels are presented here:
0.7, 3.5, 4.0, 4.9, 5.5, 7.0, 7.4, 8.1, 8.4
What is the 95% confidence interval for the mean percent change?
(3.5653, 7.4347)
500
This calculator command can be used to find the area under a normal distribution and above an interval.
What is normalcdf?
500
A soft-drink machine can be regulated so that it discharges an average of µ ounces per cup. If the ounces of fill are normally distributed with a standard deviation of 0.4 ounces, what value should µ be set at so that 6-ounce cups will overflow only 2% of the time?
µ=5.18
500
This is a type of experimental design where study participants are paired up based on key variables, or shared characteristics, relevant to the topic of the study. Then, one member of each pair is placed into the control group while the other is placed in the experimental group
Matched-pairs design
500
Suppose that you are looking for a student at your college who lives within five miles of you. You know that 55 percent of the 25,000 students do live within five miles of you. You randomly contact students from the college until one says he or she lives within five miles of you. What is the probability that you need to contact up to four people?
.96
500
At the end of every school year, the state administers a reading test to a SRS drawn from a population of 100,000 third graders. Over the last five years, students who took the test correctly answered 75% of the test questions. What sample size should you use to achieve a margin of error equal to 4%, with a confidence level of 95%?
451