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    • Thread Starter

    A factory makes both rods and copper tubes, with diameters expressed in
    millimetres. Due to variations in the manufacturing process, it is known
    that the internal diameter of a copper tube is N (22, 0.4²), while the diameter
    of a rod is N (21.5, 0.3²).

    • Find the proportion of tubes with an internal diameter less than
    • Find the proportion of rods with a diameter greater than 21.4mm
    • Find the proportion of rods with a diameter between 21.6mm and
    • A rod and tube are chosen at random. Find the probability that the
    rod will not pass through the tube.

    1) tube: T~N (22, 0.4²)
    So you want P(T < 21.4)

    Which part did you want help with?
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