Two extrusion machines that manufacture steel rods are being

Two extrusion machines that manufacture steel rods are being compared. In a sample of 1000 rods taken
from machine 1, 960 met specifications regarding length and diameter. In a sample of 600 rods taken from
machine 2, 582 met the specifications. Machine 2 is more expensive to run, so it is decided that machine 1
will be used unless it can be convincingly shown that machine 2 produces a larger proportion of rods meeting
speci cations.
(a) State the appropriate null and alternate hypotheses for making the decision as to which machine to use.
(b) Compute the p-value.
(c) Which machine should be used?

Solution