{module [79]}

Disclaimer: I did not create nor do I own these videos. I have simply embedded them, courtesy of YouTube.

{module [79]}

Disclaimer: I did not create nor do I own these videos. I have simply embedded them, courtesy of YouTube.

Here is an example problem worked through completely:

Here's Example 2!

And Example 3!

{module [79]}

normalpdf(x,?,?)

The sample standard deviation is almost the same formula as Lowercase Sigma = Population Standard Deviation, except that the denominator calls for N - 1 (one less than the number of values given).

**Command Syntax**

invNorm(*percentile*[,*?*, *?*])

**Menu Location**

Press:

- 2ND DISTR to access the distribution menu
- 3 to select invNorm(, or use arrows.

**Example:** Suppose X represents the scores on an exam and is normally distributed with mean 85 and standard deviation 10.

We want to find the value of x such that 90% of the distribution is below it. This means we are looking for the 90th percentile.

1) Press 2nd DISTR 3. This brings up InvNorm(

2) Type .90 comma 85 comma 10

3) Press ) button.

4) Press ENTER

The value you get is the 90th percentile for X.

**Menu Location**

Press:

- 2ND DISTR to access the distribution menu
- 2 to select normalcdf(, or use arrows.

normalcdf( start, end, mean, std_dev)

**For the standard normal distribution: normalcdf(-1,1**

**For the normal distribution with mean 10 and std. dev. 2.5:** normalcdf(5,15,10,2.5