Question

Please label and show each step.

3. Four different paints are advertised to have the same drying times. To verify the manufacturer’s claim, seven 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. Below are the results which may be imported into MSExcel for analysis: (Assume the populations are normally distributed, the populations are independent and the population variances are equal)

Paint 1	Paint 2	Paint 3	Paint 4
120	120	128	117
130	112	131	122
121	121	131	123
126	118	129	115
126	118	127	123
114	121	126	126
117	118	137	126

1. Write the Null and Alternative hypothesis to test whether there is a difference in dry time between the samples of each paint?

2. What statistic would you use to analyze this?

3. At a 0.05 level of significance, what would be your decision rule?

4. From your analysis, is there a difference between drying times?

5. If there was a difference in dry times how would you determine which paint has the different drying time? (i.e. what formula would you use and what is your decision criteria?) (this is not asking for a calculation)

Answer 1