### PDF

Given a probability density function find the mean, median and mode of the distribution.

### Scale Invariance

By exploring the concept of scale invariance, find the probability that a random piece of real data begins with a 1.

### PCDF

When can a pdf and a cdf coincide?

# Into the Exponential Distribution

##### Stage: 5 Challenge Level:
You might wish to recall the form of the pdf for an exponential distribution with parameter $\lambda$ is
$$f(x) = \lambda e^{-\lambda x}$$
Also, this is a probability density function. What does this say about the area under the graph?