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 DATA file Paint 1 Paint 2 144 133 142 146 130 Paint 3 128 137 135 124 141 133 143 137 136 131 Paint 4 150 142 135 140 153 At the α-.05 level of significance, test to see whether the mean drying time is the same for each type of paint. a. Compute the values identified below (to 2 decimals, if necessary) Sum of Squares, Treatment Sum of Squares, Error Mean Squares, Treatment Mean Squares, Error b. Calculate the value of the test statistic (to 2 decimals)

Answer 1

a)

a) H0: There is no significance difference among the mean drying time of 4 paints
H1: There is significance difference among the mean drying time of 4 paints
Let the los be alpha = 5%

	1	2	3	4	5	Total	Ti^2/ni
Paint 1	128	137	135	124	141	665	88445
Paint 2	144	133	142	146	130	695	96605
Paint 3	133	143	137	136	131	680	92480
Paint 4	150	142	135	140	153	720	103680
		Sum of square =		381902	Total G	2760	381210

Here P-value > alpha 0.05 so we accept H0

Thus we conclude that there is no significance difference among the mean drying time of 4 paints