A study was carried out to determine if coating significantly affects the conduc
ID: 2936986 • Letter: A
Question
A study was carried out to determine if coating significantly affects the conductivity of a low-e fluorescent bulb. The following conductivity data were taken. The results are given below Coating Type Conductivity 143 152 134 129 147 141 149 133 127 148 150 137 132 132 144 146 143 127 129 142 Perform a set of Scheffe Tests to determine which, if any of the 5 experimental conditions differs significantly from the other(s). Which of the following is true? Coating 1 is significantly more conductive than coatings 3 and 4; Coating 2 is significantly more conductive than coatings 3 and 4; O C. Coating 5 is significantly more conductive than coatings 3 and 4; Coatings 3 and 4 are not significantly different from each other in conductivity: Coatings 1, 2, and 5 are not significantly different from each other in Conductivity All of the aboveExplanation / Answer
Here,
The mean of all the coatings are
Mean difference table
Here Critical value from Scheffe's test = sqrt[(k-1) MSE * fcr * (2/n) ]
Here MSE = SSE/dF = 243.25/15 = 16.2167
Fcrfor dF = 4,15 => Fcr = 3.0555
= sqrt [ 4 * 16.2167 * 3.0555 * (2/4) ]
= 9.955
SO if Mean difference is greater than scheffes' value that coatings are different.
so Option 1 is correct here. Coating 1 is different from coating 3 and 4.
Option 2 is also correct. Coating 2 is different from coating 3 and 4.
Option 3 is also correct. Coating 5 is different from coating 3 and 4.
Option 4 is also correct as mean difference between coating 3 and coating 4 are less than scheffes' value.
Option 5 is also correct. as mean difference between coating 1, coating 2 and coating 5 are less than scheffes' value.
ALl options are correct here.
Groups Count Sum Average 1 4 580 145 2 4 581 145.25 3 4 526 131.5 4 4 517 129.25 5 4 581 145.25Related Questions
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