Probability
Random Vocab
Designing Studies
Types of Bias
Miscellaneous
100
Given two events, E and F, such that P(E)=.34, P(F)=.45, and P(E or P)= .637, then the two events are
What is independent but not mutually exclusive.
100
The use of a regression line for prediction far outside the interval of values of the explanatory variable x used to obtain the line. Such predictions are often not accurate.
What is extrapolation
100
Sampling error occurs when
What is when a sample statistic is used to estimate a population parameter
100
If you take a sample of who prefers coke or Pepsi from everyone walking out of the library through out the day, what kind of sampling bias would this be
What is convenience sampling bias
100
53% of adults say they have trouble sleeping. If a doctor contacts an SRS of 85 adults, what is the probability that over 55% will say they have trouble sleeping
What is .3558
200
If P(A)=.25 and P(B)=.34, what is P(A and B) if A and B are independent
What is .505
200
A variable that is not among the explanatory or response variables in a study but that may influence the response variable.
What is a lurking variable
200
Which of the following is most important in minimizing the placebo effect
What is blinding and a control
200
If you're sampling a neighborhood for which tv provider they have and 12% of your samples don't reply, what kind of sampling bias is this
What is non response bias
200
Which statements are true 1. By the Law of Large Numbers, the mean of a random variable will get closer and closer to a specific value 2. The standard deviation of a random variable is never negative 3. The standard deviation of a random variable is 0 only if the random variable takes a lone single value
What is 2 and 3
300
You win a game if you flip a coin with heads coming up exactly 50 percent of the tosses. Would you rather flip 10 times or 100 times
What is 10 times because .246 > .080
300
The probability, computed assuming H0 extreme than the one actually observed
What is the pvalue
300
What is most useful in establishing cause and effect relationships
What is a controlled experiment
300
If we are taking a sample of whether or not a student is enrolled in a language class, but we only sample from people sitting in D hall, what kind of sampling bias is this
What is under coverage bias
300
If every man married a woman who was exactly 3 years younger than he, what would be the correlation between ages of married men and women
What is 1
400
An insurance company charges $900 annually for auto policies for teens. The policy specifies the company will pay $1500 for a minor accident and $8000 for a major accident. If the probability of a teenager having a minor accident during the year is .15 and of having a major accident is .5, how much can the insurance company expect to make on 10 policies.
What is $2750
400
Measures the direction and strength of the linear relationship between two quantitative variables
What is correlation
400
A newspaper advice columnist asks her readers if they would have married their current spouse if they had to do it over again. Of the 25000 responses 80% said no. What does this show
What is the survey is meaningless because of voluntary bias
400
If we send out a survey to determine what percent of people are voting for a certain mayor in a city but included in the survey you used negative words to describe the opposing senator then what type of sampling bias is that
What is wording of question bias
400
If the standard deviation of a set of observations is 0, you can conclude
What is that all observations are the same value
500
Suppose 80% of jurors come to a just decision. In a jury of 6 people, what is the probability more than half come to a just decision
What is .90112
500
An observation that lies outside the overall pattern of the other observations.
What is an outlier
500
A sales representative wishes to survey her client base of 47 companies. She has 47 business cards from her contacts in the companies and decides to drop them all in a small box, mix them up, and reach in to pick 5 cards for her sample. This is and example of which type of sampling
What is a simple random sample
500
If we are trying to sample RiverBluff for if students shower in the morning or at night but we only interview people who enter the school by student parking then this is what type of bias
What is convenience sampling bias
500
What is bias in conducting surveys
What is a tendency to favor the selection of certain members of a population
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