Z Score
What is a Z score?
The number of standard deviations a value lies away from the mean
P represents what in a binomial?
P represents the probability of the event of interest occuring
Given a normal distribution, what is the probability a z score will be in between 1.1 and 3.5?
.1354
What is P(A)
Probability of event A
What is formula for mean?
np
If a z score is negative, what does this imply?
it lies below the mean
N in binompdf represents what?
N represents the number of items/individuals in the sample
.314 Given a normal distribution, what is the probability The z-score to the right?
.485
What is P(A bar)
All of the events besides event A
What is formula for variance?
npq
If a z score is over 1, what does this imply?
The value we are calculating the z score for is over one standard deviation away from the mean
X represents what in the binompdf formula in a calculator?
X represents successes we are examining.
Given a normal distribution, what is the probability a z score will be in between -1.1 and 2.34?
.8547
What does or means?
It means that we need to use rule of addition
What does fewer than 4 means?
it means we will input formula of Binomcdf and the number will be 3, then we will have to subtract it from 1.
interpret a z score of 1.1
The value we calculated the z score for lies 1.1 standard deviations above the mean
The probability of guessing a question correctly is 1/4 (multiple choice). Assume the quiz has 13 questions. If we are testing the probability of getting 7 correct, what is P, X, and N
P= .25, X= 7, N= 13.
X=24, m=19.8, o=1.1, z-score?
24.3-19.8/1.1=4.09
What does and stands for?
Mutliplication rule
What do we use normalcdf for?
For finding probability of the area.
When calculating the area in between two z scores in a calculator using normalcdf, the mean is ____ and the standard deviation is ____
0, 1
The probability of guessing a question correctly is 1/4 (multiple choice). Assume the quiz has 13 questions. What is the probability of getting 7 correct by guessing?
binompdf(13, .25, 7) =.0186
Given a normal distribution, what is the probability a z score will be in between -2.56 and 1.25?
.8891
What is given?
P(A) given P(B)
What do we use invnorm for?
For finding Z-score