Question

Paint-Drying Robots. How long it takes paint to dry can have an impact on the production capacity of a business. In May 2018, Deal’s Auto Body & Paint in Prescott, Arizona, invested in a paint­drying robot to speed up its process (The Daily Courier website, https://www.dcourier.com/photos/2018/may/26/984960336/). An interesting question is, “Do all paint­drying robots have the same drying time?” To test this, sup­ pose we sample five drying times for each of different brands of paint­drying robots. The time in minutes until the paint was dry enough for a second coat to be applied was recorded. The following data were obtained.
Robot 1: 128 137 135 124 141

Robot 2: 144 133 142 146 130
Robot 3 : 133 143 137 136 131
Robot 4: 150 142 135 140 153

At the a = .05 level of significance, test to see whether the mean drying time is the same for each brand of robot

Answer 1

Using Minitab software, (Stat -> ANOVA -> One way), we get the following output :

Here,

The value of F statistic = 2.54

and P-value = 0.093

Since P-value > 0.05, so we fail to reject H₀ at 5% level of significance and we can conclude that the mean drying time is not significantly different for different brands of robot.