The density function of the continuous random variable x, the total number of hours, in units of 100 hours, that a family runs a vacuum clea

Question

The density function of the continuous random variable x, the total number of hours, in units of 100 hours, that a family runs a vacuum cleaner over a period of one year is given below: f(x) = { x, 0 < x < 1 8 − x, 1 ≤ x < 2 0, otherwise Find the average number of hours per year that families run their vacuum cleaners?

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Trung Dũng 6 days 2021-07-18T23:18:28+00:00 1 Answers 1 views 0

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    2021-07-18T23:20:08+00:00

    Answer:

    1000 hours

    Step-by-step explanation:

    ∫xf(x)dx = ∫x*xdx (1,0) + ∫x*(8-x)dx (2,1)

    ∫xf(x)dx = ∫x²dx (1,0) + ∫8x – x²dx (2,1)

    ∫xf(x)dx = ∫x²dx (1,0) + ∫8xdx (2,1) – ∫x²dx (2,1)

    ∫xf(x)dx = x³/3(1,0) + 8x²/2 (2,1) – x³/3(2,1)

    ∫xf(x)dx = 1/3 + 8(4/2 – 1/2) – (8/3 – 1/3)

    ∫xf(x)dx = 1/3 + 8(2-0.5) – (7/3)

    ∫xf(x)dx = 1/3 + 8(1.5) – 7/3

    ∫xf(x)dx = 1/3 + 12 – 7/3

    ∫xf(x)dx = – 6/3 + 12

    ∫xf(x)dx = – 2 + 12

    ∫xf(x)dx = 10

    The average number of hours the family runs their vacuum cleaner in units of 100 hours

    100 * 10 hours = 1000 hours

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