One hundred 1.5 dtex polyester fibres with density of 1.35 g/cm3 are tested on a CRE tensile tester. 95% confidence range of main tensile properties are follows
Tenacity (gf/tex): 35 5.32
Elongation (%) : 30 7
Initial Modulus (gf/tex) : 35 9
Question 57 (Textile Engineering & Fibre Science)
99% confidence range of tenacity in gf/tex is
(A) | 35 9 |
(B) | 35 5 |
(C) | 35 7 |
(D) | 35 9 |
[Show Answer]
Option C is correct.
95% confidence range of main tensile properties are follows
Tenacity (gf/tex): 35 5.32
Elongation (%) : 30 7
Initial Modulus (gf/tex) : 35 9
Now, find 99% confidence range tenacity in gf/tex=?
Let, S.E(standard error at 95% confidence interval of tenacity)=
S.E(standard error at 99% confidence interval of tenacity)=
By formula in 95% confidence range-
……………………(1)
Formula in 99% confidence range-
…………………..(2)
Divide both the equations-
Now,
99% confidence range tenacity in gf/tex=35
99% confidence range tenacity in gf/tex=35 (Ans)