The next four questions refer to the following information: Two
methods, A and B, are available for teaching a certain industrial
skill. There is a 95% chance of successfully learning the skill if
method A is used, and an 80% chance of success if method B is used.
However, method A is substantially more expensive and is therefore
used only 25% of the time (method B is used the other 75% of the
time). The following notations are suggested: A—method...