Download 11.3 Calculator Notes

TI-84
#1: normalcdf cdf = Cumulative Distribution Function
This function returns the cumulative probability from zero up to some input value of the random
variable x. Technically, it returns the percentage of area under a continuous distribution curve from
negative infinity to the x. You can, however, set the lower bound.
Syntax: normalcdf (lower bound, upper bound, mean, standard deviation)
The Normal Probability Distribution menu for the TI-83+/84+ is found under DISTR (2nd VARS).
NOTE: A mean of zero and a standard deviation of one are considered to be the default values for a normal distribution
on the calculator, if you choose not to set these values.
Default is to find a percentage (probability) between two z-scores (with a mean of 0 and a standard deviation
of 1). To find a percentage (probability) for all z-scores below -.92, use a lower bound of an extreme z-score
value like -99999 and an upper bound of -.92. Result is .179 or 17.9%
To find a percentage (probability) between 2 data values, use the full syntax of
normalcdf (lower bound, upper bound, mean, standard deviation).
To find the probability from 65 to 80 with a mean of 70 and standard deviation of 4.5, the screen will look like this:
Some advanced TI calclators will have a pop up menu to input values that will look like this:
#2: invNorm( inv = Inverse Normal Probability Distribution Function
This function returns the x-value given the probability region to the left of the x-value.
(0 < area < 1 must be true.) The inverse normal probability distribution function will find the precise
value at a given percent based upon the mean and standard deviation.
Syntax: invNorm (probability, mean, standard deviation)
NOTE: A mean of zero and a standard deviation of one are considered to be the default values for a normal distribution
on the calculator, if you choose not to set these values.
#3: normalpdf pdf = Probability Density Function
This function returns the probability of a single value of the random variable x. Use this to graph a
normal curve. Using this function returns the y-coordinates of the normal curve.
Syntax: normalpdf (x, mean, standard deviation)
To find ShadeNorm(, go to DISTR and right arrow to DRAW.
Choose #1:ShadeNorm(.
ShadeNorm (lower bound, upperbound, mean, standard deviation)
You can also change the mean and standard deviation for data set as shown below
TI Nspire
Graphing with normpdf