Elementary statistics

posted by .

Nine apples, four of which are rotten, are in a refrigerator. Three apples are randomly selected without replacement. Let the random variable x represent the number chosen that are rotten. Construct a table describing the probability distribution, then find the mean and standard deviation for the random variable x.

question: WHAT STEPS WERE USED TO GET THE ANSWER?

this is the table

X P(x)

0 0.167
1 0.500
2 0.300
3 0.033

• Elementary statistics -

The total number of outcomes is 9C3, because there are nine apples and you are choosing 3 where order doesn't matter.

P(0) = 5C3 / 9C3

because there are 5 good apples and you need to choose 3.

P(1) = 5C2*4C1 / 9C3
P(2) = 5C1*4C2 / 9C3
P(3) = 5C0*4C3 / 9C3

• Elementary statistics -

THANK YOU SO MUCH I have been stumped on this question for hours on two different occasions, I am so glad you cleared this up for me.

Similar Questions

1. maths

from a batch of 10 eggs 3 are rotten.2 eggs are selected in succession.Find the probability that(a)both are rotten (b)only 1 is rottewn and at least 1 is fresh. b) Probability(1rotten, 1fresh)=3/10*7/9 Notice how the probabality after …
2. statistics

Three cards are randomly chosen, without replacement, from a standard deck of 52. The random variable X represents the number of hearts cards chosen. Construct the probability distribution for X.
3. Math

Apples are sold in cartons of 25. David bought home 2 cartons an found 3 rotten apples in the first carton. There were thrice as many rotten apples in the second carton. 1. Find the probability of randomly selecting a good apple from …
4. maths

6 out of 20 apples were rotten what percentage of the apples were rotten
5. Math

A bag of five apples contains three ripe apples and two rotten apples. If a ripe apple is selected first, what is the probability that a second apple selected is rotten?
6. Probability

you need 4 eggs , there are 12 eggs in the refrigerator but do not realise that 2 of these are rotten . what is the probability that none is rotten of the 4 eggs you choose at random ?
7. Maths

In a basket of apples and oranges. 15% of te he fruits are rotten. 30% of the apples and 10% of the oranges were rotten. Find the ratio of the number of apples to the number of oranges.
8. maths

a fruit seller buys 712 fruits ,of which 3/4 are apples. of all apples that he bought 1/3 were found to be rotten. if he sold all the good apples at Rs.5 1/4 each.how much money did he receive on selling all the good apples.
9. Statistics

There are ten Cortland, seven Gala and eight Macintosh apples in a basket. You pick three apples from the basket. a) What is the probability that three picked apples are all Gala or all Macintosh?
10. math,

out of 450 apples in a shop the 85 apples are found to be rotten.

More Similar Questions