For Exercises 7.75 and 7.76, see page 402; for 7.77 and 7.78, see page 404; for 7.79 and 7.80, see page 406; and for 7.81 see page 408.
7.76 Changes in sample size
Suppose that, in the setting of the previous exercise, you have the resources to contact 40 recent graduates. If all respond, will your margin of error be larger or smaller than $5000? What if only 50% respond? Verify your answers by performing the calculations.