Use the Following Information for Questions

Essay

Use the following information for questions:
At a soap and shampoo factory, employees work in three different shifts: morning, evening, and night. At the shampoo production line, each shift produces six batches of shampoo. The quality control inspector wishes to compare the pH level of the shampoo between the different shifts and between the different batches. Several bottles of shampoo are randomly selected from each batch during each shift. The SPSS output is provided below.
-The profile plot given below was obtained from these data. What feature of this profile plot tells us that there is a main effect due to shift?