Modeling and STAT first half

Question 1

Population definition

Answer 1

A population is the entire collection of objects or outcomes about which information is sought. (tangible vs. conceptual)

Question 2

Sample definition

Answer 2

A sample is a subset of a population, containing the objects or outcomes that are actually observed.

Question 3

Bayes theorem is…

Answer 3

the probability of occurrence of an event related to any condition. It is also considered for the case of conditional probability. Bayes theorem is also known as the formula for the probability of “causes”.

Question 4

Bayes theorem formula

Answer 4

P(A|B) = (P(B|A) * P(A)) / P(B)

Question 5

Mutual Exclusivity is…

Answer 5

When the outcomes of different trials have nothing in common. Mutual exclusivity is only possible when
P(A and B) = 0

Question 6

Permutations Rule

Answer 6

If you are taking n elements from a set of N elements and arranging the n elements in a distinct order, the number of different results is,
P = N! / (N-n)!

Question 7

Suppose that we have a fuse box containing 20 fuses, of which 5 are defective. If 3 fuses are selected at random and removed from the box in succession without replacing the first, what is the probability that both fuses are defective?

Answer 7

(5÷20) * (4÷19) * (3/18)
= 0.0009

Question 8

A bag contains 100 balls numbered from 1 to 100. One ball is drawn from the bag. What is the probability that the number on the ball selected will be odd or greater than 80?

Answer 8

P(ODD) = 0.5 , P(X>80) = 19/100
P( A or B) = P(A)+P(B) - P(A and B)
P(0.5) + P(19/100) - P(0.095)
= 0.59