Statistics for Decision- Making in Business - Maricopa Community ...

Probability (Relative Frequency)
Chapter 5
Continuous Probability Distributions
Up until this point, we have only considered distribution that have discrete values – non-negative
integers. There are many variables, however, that are continuous in nature. In fact, almost every
variable you studied in algebra and calculus was continuous!
Take, for example, heights of NBA basketball players, hourly wage, response time of a database
server, temperature, depth of a lake, the value of a share of Intel stock, and the lifespan of a car
engine, to name just a very few. These are all variables that can take on infinitely many values,
even within a limited range. For example, the response time of a database could be 0 seconds and
1 second. It could be 0.01 seconds, 0.00001 seconds, or 0.98727495 seconds.
5.1 The Ideas Behind the Continuous Distribution
5.1.1 Conceptual Approach to Continuous Distributions
Think back to a discrete distribution. The probability of a particular value was found by
observing the height of the relative frequency bar. While relative frequency represents the
percentage of observations found to have the value specified, it can also be thought of as a
probability, if we feel that it accurately models predictions that we might use it for. Consider the
example below showing the number of children in a classroom of 30 that are likely to likely to
have the flu.
Number of Children with Flu in a Class
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
0.4
0.2
0.14
0.16
0.1 0.1
0 1 2 3 4 5
Number of Children w/Flu
Statistics for Decision-Making in Business © Milos Podmanik Page 158