The signed area of the region is the area such that: The area of the graph on or above the x-axis is defined as positive. The area of the graph below the x-axis is defined as negative.

## Can the area of a region be negative?

“Areas” measured by integration are actually signed areas, meaning they can be positive or negative. Areas below the x-axis are negative and those above the x-axis are positive.

## What is the physical meaning of the area under the curve?

Originally Answered: What does an area under the curve really mean? Area under the curve basically signifies the magnitude of the quantity that is obtained by the product of the quantities signified by the x and the y axes.

## What does normal CDF calculate?

Normalcdf is the normal (Gaussian) cumulative distribution function on the TI 83/TI 84 calculator. If a random variable is normally distributed, you can use the normalcdf command to find the probability that the variable will fall into a certain interval that you supply.

## What is the difference between normal CDF and PDF?

Normalpdf finds the probability of getting a value at a single point on a normal curve given any mean and standard deviation. Normalcdf just finds the probability of getting a value in a range of values on a normal curve given any mean and standard deviation.

## What does InvNorm mean on a calculator?

The InvNorm function (Inverse Normal Probability Distribution Function) on the TI-83 gives you an x-value if you input the area (probability region) to the left of the x-value. Sample question: Find the 90th percentile for a normal distribution with a mean of 70 and a standard deviation of 4.5.

## What is the difference between Normalcdf and invNorm?

You use normalcdf when you want to look for a probability, and you use invnorm when you’re looking for a value associated with a probability.

## What is Normalpdf on a calculator?

#1: 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)