Higher Engineering Mathematics

Assign-17-H8152.tex 23/6/2006 15: 16 Page 626

626 STATISTICS AND PROBABILITY

determine if the distribution gives a ‘too good’ fit

at a level of confidence of 90%. (25)

7. A fishing line is manufactured by two processes,
   AandB. To determine if there is a difference in the
   mean breaking strengths of the lines, 8 lines by
   each process are selected and tested for breaking
   strength. The results are as follows:

ProcessA 8.6 7.1 6.9 6.5 7.9 6.3 7.8 8.1

ProcessB 6.8 7.6 8.2 6.2 7.5 8.9 8.0 8.7

Determine if there is a difference between the

mean breaking strengths of the lines manufac-

tured by the two processes, at a significance level

of 0.10, using (a) the sign test, (b) the Wilcoxon

signed-rank test, (c) the Mann-Whitney test.

(15)