Question: Kaiser's Ice Cream Parlour hires workers to produce milk shakes. The market for milk shakes is perfectly competitive, and the price of a milk shake is $4. The labour market is competitive, and the wage rate is $40 a day. The table shows the workers' total product schedule.
Number of Quantity produced
workers (milk shakes per day)
1 7
2 21
3 33
4 43
5 51
6 55
Calculate the marginal product of hiring the fourth worker and the fourth worker's value of marginal product.