BIOL 582. Lecture Set 3 Probability Distributions. BIOL 582. Review. We learned that we could empirically generate distributions for things like test statistics Recall from R examples,. BIOL 582. Review.
Lecture Set 3
By changing frequency to density, the height of the distribution at any point measures the probability of the value found on the x axis
Red line is the probability density function for the standard normal distribution. It is “theoretical”. If the data fit this line well, it can be used as a proxy for estimating the probability of any event described on the x axis
Binomial distribution for n = 20
p = 0.1 (blue), p = 0.5 (green) and p = 0.8 (red)
x-axis is k (number of events = “success”)
Taken from Wikipedia
Notice that as n increases (meaning the df increases), the t-distribution converges on the normal distribution. One way to think of the t-distribution is that it is a standard normal distribution, corrected for small sample sizes.