10.77 Industrial workers who are required to wear respirators were checked periodically to see that the equipment fit properly. From past records, it was expected that 1.2% of those checked would fail (i.e., their equipment would not fit property).
The data from one series of checks were as follows:

Can the asumption of the constant 1.2% failure rate be rejected at the 5% significance level?

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Time After First Measurement Number of Workers Observed Expected Failures (months) Measured Failures (1.2% of col. 2) 0-6 28 1 0.34 6-12 92 3 1.10 12-18 270 1 3.24 18-24 702 9 8.42 24-30 649 10 7.79 30-36 134 0 1.61 >36 93 0 1.12 Total 1,968 24 23.6