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Svetradugi [14.3K]
3 years ago
12

A project is graded on a scale of 1 to 5. If the random variable, X, is the project grade, what is the mean of the probability d

istribution below?
                     Probability Distribution

.45    |
.4      |                            ~
.35    |                            ~
.3      |                            ~
.25    |                            ~
.2      |                ~          ~          ~
.15     |                ~          ~          ~
.1       |    ~          ~          ~          ~          ~
.05    |    ~          ~          ~          ~          ~
0       |__~____~_____~_____~____~____
              1          2          3          4          5
                                 X
Answer Choices:  A. 0.2  B. 0.4   C. 1  D. 3
Mathematics
2 answers:
choli [55]3 years ago
8 0

The correct answer is D) 3.

The mean is 3

damaskus [11]3 years ago
5 0

Answer:

3

Step-by-step explanation:

Given that A project is graded on a scale of 1 to 5.

If the random variable, X, is the project grade, we have to find  the mean of the probability distribution below

Since X takes values as 1,2,3,4,5

from the picture given we find the frequency distribution of X

X    1    2     3     4    5     Total

f     2    4     8     4    2       20

fx    2    8    24   16  10      60

Mean =60/20 =3

Hence answer is 3

   

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Answer:

The probability is 0.8722

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Now we want to find the probability that, for 3 tested bottles, that less than two (0 or 1 ) are contaminated.

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The probability of getting a contaminated bottle in the first draw is equal to the quotient between the number of contaminated bottles and the total number of bottles, so:

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p = p₁*p₂*p₃ = (5/21)*(16/20)*(15/19)

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probability = P + Q = 0.4211 + 0.4511 = 0.8722

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