Final answer:
To calculate the average pay rate in Access, use the Total line in the query grid to select Avg for the PayRate field.
Step-by-step explanation:
To calculate the average pay rate for all employees in Access query design view, using an Employee table that includes PayRate among other attributes, you should follow these steps: First, click the summation sign to add the Total line to the query grid. Then, drag PayRate to the query grid. After that, select Avg on the Total line under PayRate. This will compute the average PayRate across all the records present in the Employee table.