Exam 8: Random Sampling and Probability

The local psychological association reports that in a particular community there are 36 analytic psychologists, 57 behaviorists, 92 cognitive psychologists, 17 Gestalt psychologists and 42 of unknown theoretical background.

A cattle breeder has 100 black cows of breed X , 50 brown cows of breed Y and 22 white cows of breed Y .

Define probability of occurrence of A or B.

Two events are independent if _________.

When events A and B are mutually exclusive but not exhaustive, p ( A or B ) equals _________.

Consider an ordinary deck of playing cards. What is the probability for the following:

For a sample to be random, all the members must have an equal chance of being selected into the sample.

Define mutually exclusive.

For continuous variables which are normally distributed, p ( A ) equals the area under the curve corresponding to A divided by the total area under the curve.

Define sampling without replacement.

Define random sample.

When a sampled score is put back in the population before selecting the next score, this process is called sampling without replacement.

If µ = 400 and s = 100 the probability of selecting at random a score less than or equal to 370 equals _________.

What is the probability that you can correctly guess the spelling of a three-letter sequence that you do not know, if the first letter is different from the second and third letters but the second and third letters may or may not be the same?

A posteriori probability refers to _________.

p ( B | A ) is read probability of B divided by A .

When two events are dependent, then p ( A and B ) = p ( A ) + p ( B ).

The Multiplication Rule concerns the joint or successive occurrence of several events.

If P + Q = 1.00 then P and Q must be _________.

If sampling is without replacement, the events are independent.