href="#fb3_img_img_ee3eef92-b815-5604-a09b-9437885d7078.png" alt="omega prime equals y element-of normal upper Omega prime"/>. Trivially, is
‐measurable, and
or slightly more than 1 euro.
The random variables and
are two equivalent ways of mathematically representing the wager. In [MTRV],
is described as a contingent form of the random variable, while
is an elementary form.
Measurability ensures that the two forms are related. To illustrate, consider , a subset in the range of the random variable
(or
. Then
which is a subset of the sample space
. Both
and
are measurable sets (trivially), and
is a measurable function, with
This kind of relationship is generally valid for contingent and elementary forms of random variables.
2.2 Probability and Riemann Sums
Elementary statistical calculation is often learned by performing exercises such as the following.
Example 4
A sample of 100 individuals is selected, their individual weights are measured, and the results are summarized in Table 2.2.Estimate the mean weight and standard deviation of the weights in the sample.
Table 2.2 Relative frequency table of distribution of weights.
| Weights (kg) | Proportion of sample |
|---|---|
| 0 – 20 | 0.2 |
| 20 – 40 | 0.3 |
| 40 – 60 | 0.2 |
| 60 – 80 | 0.2 |
| 80 – 100 | 0.1 |
Table 2.3 Calculation of mean and standard deviation.
|
|
|
x |
|
|
|
|---|---|---|---|---|---|
| 0 – 20 | 0.2 | 10 | 100 | 2 | 20 |
| 20 – 40 | 0.3 | 30 | 900 | 9 | 270 |
| 40 – 60 | 0.2 | 50 | 2500 | 10 | 500 |
| 60 – 80 | 0.2 | 70 | 4900 | 14 | 980 |
| 80 – 100 | 0.1 | 90 | 8100 | 9 | 810 |
Sometimes calculation of the mean and standard deviation is done by setting out the workings as in Table 2.3. The observed weights of the sample members are grouped or classified in intervals