Respuesta :
Answer: In total there are 40 marbles because 11+7+9+13=40
There are 7 Blue marbles, so
P(blue)=7/40
\
Disclaimer: The options were not given correctly so they are added here:
a. The theoretical probability of selecting a red marble from the bag is 27.5%.
b. The odds of selecting a yellow marble from the bag are 13 to 27.
c. The theoretical probability of selecting a blue or green marble from the bag is 2/3.
d. The odds of selecting a red or blue marble are 9/11.
Among the given statements, c. The theoretical probability of selecting a blue or green marble from the bag is 2/3. which is not true.
What is the probability of an event?
The probability of an event is the fractional value determining how likely is that event to take place. If the event is denoted by A, the number of outcomes favoring the event A is n and the total number of outcomes is S, then the probability of the event A is given as:
P(A) = n/S.
What are the odds of a given event?
When a given event suppose A, has a Probability of occurring = P(A) and Probability of not happening = 1 - P(A).
When we calculate the odds in favor of event A, the value is given by the ratio, P(A):(1 - P(A)).
When we calculate the odds against the event A, the value is given by the ratio, (1 - P(A)):P(A).
How do we solve the given question?
We are informed that a bag contains eleven red marbles, seven blue marbles, nine green marbles, and thirteen yellow marbles.
Let the event of selecting a red marble from the bag be R.
Number of outcomes favoring R = 11 (number of red marbles)
Total number of outcomes = 40 (number of marbles in the bag)
∴ The probability of the event R is P(R) = 11/40
1 - P(R) = 1 - 11/40 = 29/40
Let the event of selecting a blue marble from the bag be B.
Number of outcomes favoring B = 7 (number of blue marbles)
Total number of outcomes = 40 (number of marbles in the bag)
∴ The probability of the event B is P(B) = 7/40
1 - P(B) = 1 - 7/40 = 33/40
Let the event of selecting a green marble from the bag be G.
Number of outcomes favoring G = 9 (number of green marbles)
Total number of outcomes = 40 (number of marbles in the bag)
∴ The probability of the event G is P(G) = 9/40
1 - P(G) = 1 - 9/40 = 31/40
Let the event of selecting a yellow marble from the bag be Y.
Number of outcomes favoring Y = 13 (number of yellow marbles)
Total number of outcomes = 40 (number of marbles in the bag)
∴ The probability of the event Y is P(Y) = 13/40
1 - P(y) = 1 - 13/40 = 27/40
Now, we analyze all the options, to check for the ones which are not true.
a. The theoretical probability of selecting a red marble from the bag is 27.5%.
The probability of selecting a red marble P(R) = 11/40 =11/40 * 100% = 27.5%, which is the same we are looking for.
∴ The statement is true.
b. The odds of selecting a yellow marble from the bag are 13 to 27.
The odds of selecting a yellow marble (odds in favor) = P(Y)/(1 - P(Y)) = 13/27 or 13 to 27, which is the value we are looking for.
∴ The statement is true.
c. The theoretical probability of selecting a blue or green marble from the bag is 2/3.
The probability of selecting a blue or green marble from the bag = P(B) + P(G) = 7/40 + 9/40 = 16/40 = 2/5, which is not the value we are looking for.
∴ The statement is not true.
d. The odds of selecting a red or blue marble are 9/11.
The probability of selecting a red or blue marble from the bag
P(R+B) = P(R) + P(B) = 11/40 + 7/40 = 18/40 = 9/20.
1 - P(R+B) = 1 - 9/20 = 11/20
∴ Odds of selecting a red or blue marble (odds in favor)
= P(R+B)/(1 - P(R+B)) = (9/20)/(11/20) = 9/11, which is the value we are looking for.
∴ The statement is true.
So, among the given statements, c. The theoretical probability of selecting a blue or green marble from the bag is 2/3. which is not true.
Learn more about the odds in favor and against at
https://brainly.com/question/14350753
#SPJ2
