Stat test 2
Probability is always a value between ____ it may appear as a ____
0-1- fraction-decimal or percent
How to find the z score when given area to right or to left
Find closest number and then find corresponding closest z score when locating are to the right subtract one form the given area before locating it on the table.
The word "or" is used in ?
Independent events
The word "given" is used in ?
Conditional probabilities
Finding the value if we know the mean, standard deviation and the z score we can find the value score
Convert percentage into z score by finding closest corrusponding number use in formula x=mean + (z multiplied by standard dev)
What is the difference between theoretical probability and empirical probability?
Empirical prop tells us how often an event occurs in an actual set of experiments or observations. Theoretical probabilities are based on theory telling us about events that occur indefinitely
How do you find the area to the right in a standers normal dis curve?
Locate number on z chart this is the area to the left must subtract 1 in order to find the area to the right. This is your answer
Turning left and turning right Getting heads and tails These are examples of what?
Mutually exclusive events
For dependent events
P(A and B) p (B/A)=-------------- P(A) ! A is always the numerator
Addition rule of mutually exclusive events
P(A or B) = P(A) + P(B)
Addition Rule (Not Mutually Exclusive)
P(A or B) = P(A) + P(B) - P(A and B)
Complement rule
P(A^c) = 1 - P(A) The probability that an event will not occur is 1 minus the probability that the event will occur.
If p(A) is 0 the event is certain
not to occur
Permutation
The number of permutations of R objects chosen from n
Central limit theorem
The sampling distribution of the mean will approach the normal distribution as n increases (n>30).
to find the area to the right we have to subtract
because the z chart shows areas to the left
Mutually exclusive events
events that cannot happen at the same time
Unusual events
events that occur less than 5% of the time
In permutation the order is
important
How to find the area between in a normal dist curve?
locate area on z chart subtract big from small= final answer
Theoretical Probability
long run relative frequencies
Probability is used to _____________
measure how often random events occur
Area, proportion and probability are all the same in
normal distribution
In combination the order of selection is
not important
Independent events
p(A or B)= p(A) + p(B)
Emprical Probability
relative frequencies based on an experiment of observation
When we are looking for an area that is greater we are looking for the area to the
right
The z score of x is
score- mean divided by standard deviation
Law of Large Numbers
the larger the number of individuals that are randomly drawn from a population, the more representative the resulting group will be of the entire population or close to the true probability
If p(A) is 1 the event is certain
to occur
central limit theorem formula
x minus mean divided by the square root of the sample
