Semi-logarithmic scalesuse an arithmetic scale on the horizontal axis, but use a logarithmic scale on the vertical axis. Hence, values on the vertical axis are spaced according to their logarithms. On a semi-logarithmic scale, equal movements on the vertical axis reflect equal percentage changes.
1.C: Probability Concepts
a: Define a random variable.
A random variableis a quantity whose outcomes are uncertain. A realized random variable is a number associated with the outcome of an experiment. When rolling a conventional six-sided die, the random variable might be the number that faces up with the die stops rolling.
b: Explain the two defining properties of probability.

  1. The probability of any event "i" is between zero and one.

  2. If a set of events: E1, E2, ....En, are mutually exclusive and exhaustive, then the sum of the probabilities of those events equals one.

  • Mutually exclusivemeans that the events do not share any outcomes. Knowing that you have an outcome in one event excludes the possibility of an outcome in another event.

  • Exhaustivemeans that a given list of events represent all possible outcomes.