Intro to Probabilities

General

100

what does "P" in P(A) denote

Probability of "A"

200

what does "A" denote in P(A)?

an event

300

What is the formula for the probability of an event occuring

P(A)=# of times A occurs/total possible

400

True or False: in a probability model, the sum of probabilities should equal 100

False, should equal 1 as probabilities should be represented by values between 0 and 1

500

Sampling from a population is a _____ experiment

probability

Calculating probability

100

There are 10 blocks in a bag:

2 green

3 Red

4 blue

1 yellow

what is the probability of pulling the yellow block

.1 or 10%

200

There are 10 blocks in a bag:

2 green

3 Red

4 blue

1 yellow

what is the probability of pulling a red block

.3 or 30%

300

There are 12 blocks in a bag:

3 green

3 Red

4 blue

2 yellow

what is the probability of pulling a red block

.1667 or 16.67%

400

What is the probability of rolling an even number on a fair die

.5 or 50%

500

There are 15 blocks in a bag:

7 green

3 Red

4 blue

1 yellow

what is the probability of not pulling a blue block

.7333 (1-P(A) = 1-.2667)

Sample Space and "Or"

100

Given the following, what is the sample space.

Green x 4

Blue x 7

Red x 8

Orange x 3

s={Green, Blue, Red, Orange}

200

Given the following, Find the sample space if two blocks are drawn from a bag one at a time

Blue x 6

Green x 7

Yellow x 8

Orange x 2

s={BB,BG,BY,BO,BG,GB,GG,GY,GO,YB,YG,YY,YO,OB,OG,OY,OO}

300

What is the probability of pulling a blue or green ball?

Blue x 6

Green x 7

Yellow x 8

Orange x 2

.6087

400

if the probability of an event is .5647, what is P(A^c)

P(A^c)=P(A)-1 ANS=.4353