SOLUTION: Determine whether each of the distributions given below represents a probability distribution. Justify your answer. (A) x 1 2 3 4 P(x) 1/4 1/12 1/3

Algebra ->  Probability-and-statistics -> SOLUTION: Determine whether each of the distributions given below represents a probability distribution. Justify your answer. (A) x 1 2 3 4 P(x) 1/4 1/12 1/3       Log On


   



Question 622122: Determine whether each of the distributions given below represents a probability distribution. Justify your answer.

(A)
x
1
2
3
4

P(x)
1/4
1/12
1/3
1/6



(B)
x
3
6
8

P(x)
0.2
2/5
0.3



(C)
x
20
30
40
50

P(x)
3/10
-0.1
0.5
0.3




Found 3 solutions by solver91311, vleith, ewatrrr:
Answer by solver91311(24713) About Me  (Show Source):
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A set of data is a probability distribution if and only if all of the data elements are positive and the sum of all the data elements is 1.

John

My calculator said it, I believe it, that settles it
The Out Campaign: Scarlet Letter of Atheism


Answer by vleith(2983) About Me  (Show Source):
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I will say the first two are and the last one is not.
The first two have a list of values, where the probabilities are all between 0 and 1 with a total of all listed of 1 or less. For those first two, assuming there are other values of x which are NOT shown, the listed values are between 0 and 1 AND their total is less than 1.
The third one has a probability entry (the secocd one) less than 0. The total is 1, but you can't have a probability less than 0.

Answer by ewatrrr(24785) About Me  (Show Source):
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Hi,
a. Yes, probabilities total to 1
b. No, probabilities do not total to 1 (9/10)
c. No, Probabilites must be 0 ≤ p(x)≤ 1 P(x=30) = -.1 , not allowed