The Directors of a large company introduced a new pay structure for manual employees, the aim is to reward for higher productivity. After introducing the new pay structure for some time, a random sample of employees was selected and the number of items produced per hour is given below:

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• Obtain a 95% confidence interval for the mean number of items produced per hour.

• In the past the average number of items produced per hour by labour force was 48 per hour. Test whether the new pay structure has increased the productivity of the employees.