probability and normal distribution

Question 1

definition of equally likely outcomes probability

Answer 1

relies on the assumption that each of the possible outcomes of an experiment is equally likely

Question 2

equally likely outcomes probability equation

Answer 2

P = number of equally likely outcomes in A/ total no. of outcomes

Question 3

relative frequency definition of probability

Answer 3

necessitates repeating the experiment a large number ofo times and noting the proportion of times the event of interest occurs

Question 4

properties that probabilities hold irrespective of definition used

Answer 4

probability must be between 0 and 1
P(a)=0 if and only if A is impossible
P(A)=1 if and only if A is certain

Question 5

what is the probability of A not happening known as

Answer 5

complement of A
P(notA) = 1 - P(A)

Question 6

addition law states that…

Answer 6

if 2 events, A and B, are mutually exclusive then the probability of either event A or B occurring, denoted by P(A or B) is
P(AorB) = P(A) + P(B)

Question 7

multiplication law states that…

Answer 7

if 2 events are independent (the risk of 1 event occurring is unaffected by the other event occurring) then the probability of both A and B occurring is
P(AandB) = P(A) x P(B)

Question 8

normal distribution curve is

Answer 8

symmetrical about the mean and bell-shaped

Question 9

what does the standard deviation determine

Answer 9

the width of the distribution
the larger the std deviation, the wider and shorter the distribution

Question 10

in any frequency distribution, the area under the entire curve is exactly…

Answer 10

1

Question 11

what is standard normal distribution

Answer 11

normal distribution with mean 0 and standard deviation 1