Question

Miss Davidson ran a sit-up competition among her P.E. students and monitored how many sit-ups each student could do. Number of sit-ups Number of students 76 3 79 5 175 2 X is the number of sit-ups that a randomly chosen student did. What is the expected value of X? Write your answer as a decimal.

Answer 1

Let the total number students be s. Then

s = 3 + 5 + 2= 10

x | Number of students(n) | Pr(x) | xPr(x)

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76 | 3 | 0.3 | 22.8

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79 | 5 | 0.5 | 39.5

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175 | 2 | 0.2 | 35

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`\sum \text{xPr(x) = 22.8 + 39.5 }+\text{ 35 = 97.3}`
`\text{ The expected value is }\sum \text{xPr(x)}`

Therefore, the expected value of x is 97.3