University of the West of England

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Two-sample t-test (glass refractive index)

 

Link to Video Answer

 

In a forensic analysis, the refractive indices of two samples, A and B, of glass fragments are measured. Sample, A, collected from a broken window contains 7 fragments and the sample, B, from the clothing of a suspect contains 6 fragments. The last three digits in the measured values of their refractive indices are given below:

 

A

214

165

159

125

162

97

182

B

348

255

244

179

250

126

 

 

Use Minitab to perform hypothesis tests to investigate whether there is any significant difference between the refractive indices of the two samples -

 

i)          assuming that the samples are drawn from populations with equal variance,

 

ii)         assuming that the samples are not drawn from populations with equal variance.