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.

Excel or Minitab users: The data set is available in file namedPaint.
Paint 1 Paint 2 Paint 3 Paint 4
128 144 133 150
137 133 143 142
135 142 137 135
124 146 136 140
141 130 132 153
At the = .05 level of significance, test to see whether the mean drying time is the same for each type of paint. Compute the values identified below:
1. Sum of Squares,Treatment
2. Sum of Squares,Error
3. Mean Squares,Treatment
4. Mean Squares,Error

Answer 1

Explained below.

Explanation:

The data provided is for the dying time of four different types of paint.

One-way ANOVA can be used to determine whether all the four paints have the same drying time.

Use Excel to perform the one-way ANOVA.

Go to Data → Data Analysis → Anova: Single Factor

A dialog box will open.

Select the data.

Select "Grouping" as Columns.

Press OK.

The output is attached below.

The required values are as follows:

(1)

Sum of Squares of Treatment (Between Subjects):

SST = 330

(2)

Sum of Squares of Error (Within Subjects):

SSE = 692

(3)

Mean Squares Treatment (Between Subjects):

MST = 110

(4)

Mean Squares Error (Within Subjects):

MSE = 43.25