In a statistics class of students, have volunteered for community service in the past. If two students are selected at random from this class, what is the probability that both of them have volunteered for community service?

Question

31-03-2020
Mathematics

contestada

In a statistics class of students, have volunteered for community service in the past. If two students are selected at random from this class, what is the probability that both of them have volunteered for community service?

Respuesta :

Otras preguntas

a patient is having difficulty sitting and standing without support. if you know this is due to a spinal cord injury, in which location would you expect the dam

3. what were the differences between the counterculture and the larger anti-vietnam war movement? what were the similarities?

a four digit personal identification number (pin) is selected. what is the probability that there are no repeated digits? do not round

a u.s. grocery chain borrows money to buy a warehouse in ohio and another in italy. borrowing for which warehouse(s) is included in the demand for loanable fund

ohn sells 300 packs of candies per week at $40 per pack. the candies are ordered from a supplier who charges john $60 per order and $20 per pack. john's annual

when assessing a client with acute cholecystitis, the nurse anticipates the client's report of pain will be consistent with which description?

the nurse enters the room of a client and, without the use of the stethoscope, can hear the client wheezing. how should the nurse document this finding in the m

Abused children more readily perceive _______ in a series of human faces than children who haven’t experienced abuse.

when severe autocorrelation is indicated after a regression model has been estimated, which underlying regression assumption is violated?

in the e-test, the zone of inhibition is elliptical around the plastic strips impregnated with antibiotics. what information do you get when you know the point

ACCESS MORE

facundo3141592 facundo3141592 · Answer 1 · 2020-04-01T02:30:33+02:00

Answer:

We do not have the total number of students or volunteers.

I will put variables (and then random numbers) and solve it, then you can put the numbers that you need in the equations.

Suppose that the class has Y students, and X of these students have volunteered.

The probability of picking at random a student that has volunteered is equal to the number of students that had volunteered divided by the total amount of students:

p1 = X/Y

now, we must choose another student, but now the volunteers are X - 1, and the total number of students is also Y - 1 (because we already took one student)

now, the probability of selecting other will be:

p2 = (X- 1)/(Y - 1)

Then, the joint probability of both events is equal to the product of both probabilities:

P = p1*p2 = (X/Y)*((X-1)/(Y -1))

Suppose that there are 20 students, and 10 students that have volunteered, then the equations are:

P = (10/20)*(9/19) = 0.237