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24 21 20 22 24 An operator is observed performing a job. The following 30 job measurements (in minutes) are recorded: 21 21 24 23 22 20 21 24 20 21 23 21 21 23 22 24 22 20 23 22 23 21 20 24 23 The operator's performance is estimated about 20% slower than his normal speed. Job allowances include: basic fatigue 5%, noise level 8%, mental strain 8%, tediousness 4%. The analyst wants to establish the standard time of the job with 95% (z =1.96) confidence level and the maximum error of 0.5 minutes. Based on the above information, what is the standard time of the job? (xx - 5) Hint: Sample mean 1 = xx and sample standard deviation s= V k=1 k=1 n-1 The following additional job measurements may be needed if necessary: 22 23 21 23 24 20 22 23 22 24