General Rules
Given an event, A, what equation gives you the probability that event A will NOT occur?
What is ....
P(A') = 1 - P(A)
or
P(A')+P(A)=1
A coin is tossed 3 times. What is the probability that it lands on heads exactly one time?
What is...
HHH TTT HHT HTT TTH THH HTH THT
3/8 = .375
Events that do not impact each other's probability.
What is...
independent
What is ...
P(rolling three 4s) = P(4)*P(4)*P(4) = P(4)^3
or (1/6)*(1/6)*(1/6)= (1/6)^3
The calculator command you would use if you have a normal distribution and need to calculate the probability of an event being less than 10?
What is ...
normcdf
Given two independent events, A and B, what is the probability that event A and B occurs.
What is...
P(A and B) = P(A) * P(B)
Armando is a high school baseball player. He gets a hit 70% of the time. That means his average is 0.70. What is the probability that he gets his first successful hit on his third swing?
What is ...
0.3*0.3*0.7= 0.063
two events that cannot occur simultaneously
What is....
mutually exclusive or disjoint
The rule for the probability of pulling a red or queen from a standard deck of cards.
What is...
P(Red or Queen)= P(red)+P(queen) - P(red and queen)
The formula chart location for the standard deviation of a discrete random variable.
What is ...
Section II, first row of the table.
Given two mutually exclusive events, A and B, what is the probability that event A or event B occurs?
What is ...
P(A or B)= P(A) + P(B)
The two equations used to determine independence between 2 events.
What is...
P(A|B)=P(A)
or
P(B|A)=P(B)
two events that cannot occur together, but one must happen
What is...
complementary
The rule for finding the probability of a female given that they are an AP stats student.
True or False: When transforming random variables by factor of 3, only the mean will be multiplied by 3.
What is....
False, both the mean and standard deviation are transformed by multiplication.
Given two events, A and B, what is the probability that event A and B occurs.
What is...
P(A and B) = P(A) * P(B|A)
90% of the people who have a particular disease will have a positive result on a given diagnostic test (90% accuracy). If 5% of a certain population has the disease, what percent of that population would test positive for the disease?
What is ... using a tree diagram: positive|disease + positive|no disease, (.05)(.90)+(.95)(.10)
14% or 0.14
events that do impact each other's probability
what is ...
dependent
The probability distribution that meets the BINS conditions: Binary outcomes, Independent trials, fixed Number of trials, Same probability for success.
What is ...
binomial distribution
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True, standard deviations NEVER add; you must first change the standard deviation to the variance by squaring first.
Given two events, A and B, what is the probability that event A or event B occurs?
What is ...
P(A or B)= P(A) + P(B) - P(A and B)
or
P(A or B)= P(A) + P(B) - P(A)*P(B|A)
Two events are this if they share no outcomes in common
What is ...
disjoint or mutually exclusive
contains all of the possible outcomes
what is...
sample space
An example of this type of probability would be finding the probability that the fourth tropical storm produces the first hurricane.
What is ...
geometric distribution
The calculator steps used to find the expected value of a discrete distribution given to you as a table.
What is .... Enter the table in a list and spreadsheet, one column for the event value the second column for the probability of that event. Use Stat, Stat Calc, 1 variable stats, 1 list, select/enter column label, make sure to select a frequency list (!), Ok, and look for the x-bar.