Which describes a uniform probability model?
Responses
A drawing a red or black card from a deck of cards
B selecting a sock from 5 black socks and 10 white socks
C selecting a ball from 2 red balls and 3 yellow balls
D equally divided five section spinner with three colors
D - equally divided five section spinner with three colors.
A bag contains 6 red marbles, 6 purple marbles, and 6 yellow marbles. What is the probability of randomly selecting a yellow marble from the bag?
There are a total of 6 + 6 + 6 = 18 marbles in the bag. The probability of randomly selecting a yellow marble is the number of yellow marbles divided by the total number of marbles:
P(yellow) = 6/18 = 1/3
Therefore, the probability of randomly selecting a yellow marble is 1/3.
Student Grade
Arthur 7
Jeff 8
Anna 7
Molly 8
Sara 8
Bryan 7
Joseph 8
Michael 7
Susan 8
Maria 7
Mrs. Benton selects one student's work to display on a bulletin board each week. Each student's name is placed in a bag from which Mrs. Benton draws a name. What is the probability that an eighth grade student will NOT be selected?
There are 10 students in total, 4 of whom are in eighth grade. Therefore, the probability of selecting an eighth grade student is:
P(eighth grade) = 4/10 = 2/5
The probability of not selecting an eighth grade student is equal to 1 minus the probability of selecting an eighth grade student:
P(not eighth grade) = 1 - P(eighth grade)
P(not eighth grade) = 1 - 2/5
P(not eighth grade) = 3/5
Therefore, the probability that an eighth grade student will not be selected is 3/5 or 0.6.
A uniform probability model is one in which all possible outcomes have an equal chance of occurring. Looking at the given options:
A) Drawing a red or black card from a deck of cards: This is not a uniform probability model because different cards have different probabilities of being drawn (e.g., there are more red cards than black cards).
B) Selecting a sock from 5 black socks and 10 white socks: This is also not a uniform probability model because the white socks have a higher chance of being selected than the black socks.
C) Selecting a ball from 2 red balls and 3 yellow balls: This is not a uniform probability model because the red balls have a lower chance of being selected than the yellow balls.
D) Equally divided five section spinner with three colors: This is a uniform probability model because each section has an equal probability of being selected. Since the spinner is divided into five sections, each section has a 1/5 (or 20%) chance of being chosen.
Therefore, the correct answer is option D) equally divided five section spinner with three colors.