Gathering & Organizing Data
This term refers to the collection of all data you want information about, while a subset of that group is called a sample
a population
According to the 68-95-99.7 Rule, this is the approximate percentage of data that lies within one standard deviation of the mean
68%
ID the formula,
(x−μ)/σ
z-score
In a controlled experiment, this is the group that is subjected to no treatment or a placebo.
control group
What symbol do we use for a mean of a sample?
x-bar
What vocabulary term deals with just population? An example is the mean of everyone in the state of Nevada.
a parameter
In a normal distribution, the mean is approximately equal to this other measure of center
median
If the probability of winning is 2/5 (40%), these are the actual odds in favor of winning
2:3 odds
This is the only type of study design that can determine a cause-and-effect relationship it tries to minimize bias as much as possible.
well-designed randomized experiment
In hypothesis testing, if a simulation shows that a result is highly unlikely to occur by chance, you do what to the null hypothesis
Reject it
This sampling method involves using a rule, such as selecting every 6th person from an alphabetical list
systematic sampling
If a data set has a mean of 90 and a median of 80, the distribution is described as being skewed in this direction
skewed right
This mathematical tool is used when the order of selection matters, such as arranging 1st, 2nd, and 3rd place in a race
permutation
This experimental process involves assigning subjects to groups by chance to minimize bias
randomization
This is the symbol used for the mean of a population.
mu
This method of data collection is used when a researcher wants to investigate characteristics of a sample without influencing the subjects, such as recording fuel choices at a gas station
an observational study
For a normal distribution with μ=40 and σ=8, this is the probability that a randomly selected x-value is at least 32
84%
This is the number of ways you can select a subcommittee of 6 members from a department of 12 scientists. They all get along well. It doesn't matter the order in which they are selected; use the function that eliminates duplication.
924
To improve the validity of an experiment, researchers use this process, which is the repetition of the experiment under similar conditions
replication
Symbol for standard deviation of a population
sigma
Interviewing people as they leave a local restaurant to determine the town's eating habits is an example of this biased sampling method
convenience sampling
This rule states that approximately 99.7% of data in a normal distribution falls within this many standard deviations from the mean
3 sigma (stDev) to the left and right of mu
I'm making a smoothie and I have 10 fruits in total. I just need 4 to get my daily vitamin C. What type of problem is this and how many ways can I select the 4 fruits?
Combination; 210
Asking "Do you like the taste of our prize-winning coffee?" is an example of this flawed survey practice. Name the vocabulary term and ID what part of the question is leading.
a biased (or leading) question
This occurs when a researcher incorrectly decides that a hypothesis is false when it is actually true. An example is telling an old man they are pregnant when in reality they are not.
False Positive or Type 1 error