Four different paints are advertised as having the same drying time. To check the manufacturer's claims, five samples were tested for each of the paints. The time in minutes until the paint was dry enough for a second coat to be applied was recorded. The following data were obtained.
Paint 1 Paint 2 Paint 3 Paint 4
128 144 133 150
137 133 143 142
135 142 137 135
124 146 136 140
141 130 131 153
At the .05 level of significance, test to see whether the mean drying time is the same for each type of paint.