Question

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.

Click on the datafile logo to reference the data.

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

1. Compute the values identified below (to 2 decimals, if necessary).

   Sum of Squares, Treatment
   Sum of Squares, Error
   Mean Squares, Treatment
   Mean Squares, Error

2. Calculate the value of the test statistic (to 2 decimals).
   
3. The p-value is Selectless than .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 6
   
   What is your conclusion?
   SelectConclude not all mean drying times are equalDo not reject the assumption that the mean drying times are equalItem 7

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

Answer 1

a)

Sum of Squares, Treatment	330.00
Sum of Squares, Error	692.00
Mean Squares, Treatment	110.00
Mean Squares, Error	43.25

b) The value of the test statistic: F=2.54

c) The p-value is: between .05 and .10

Conclusion:
Do not reject the assumption that the mean drying times are equal.