Question

Q3. Figure Q3 shows deformed steel bars normally used in the construction size. It is targeted
that the diameter for the deformed steel bars is 32 mm. A sample of 15 deformed steel
barsisrandomly picked and the diameter of each one is determined, resulting in a sample
mean diameter of 30.5 mm and a sample standard deviation of P mm. By using t-test,
assess if this data suggest that the true average diameter of deformed steel bar is
something other than the target value. (NOTE: refer Appendix I for the value of P):
(a) Assess this question by using 95 % confidence level.
(b) Re-assess this question by using if a more stringent 99% confidence level is needed.
not: I = 1

p = 1

Answer 1