Question

Quantitative noninvasive techniques are needed for routinely assessing symptoms of peripheral neuropathies, such as carpal tunnel syndrome (CTS). The article “A Gap Detection Tactility Test for Sensory Deficits Associated with Carpal Tunnels Syndrome” (Ergonomics, 195: 2588 – 2601) reported on a test that involved sensing a tiny gap in an otherwise smooth surface by probing with a finger; this functionally resembles many work-related tactile activities, such as detecting scratches or surface defects. When finger probing was not allowed, the sample average gap detection threshold for m = 8 normal subjects was 1.71mm, and the sample standard deviation was 0.53mm; for n = 10 CTS subjects, the sample mean and sample standard deviation were 2.53mm and 0.87mm, respectively

(a) Does this data suggest that the true average gap detection threshold for CTS subjects exceeds that for normal subjects? Use significant level α = 0.01. 

(b) Build a 99% confidence interval for µ1 − µ2, where µ1 is the true average gap detection threshold for normal subjects, and µ2 is this value for CTS subjects.

Answer 1