(Choose 1 answer)
(See picture)
A. None of the other choices is correct
B. 6.669
C. 6.482
D. 6.729
Ε. 6.519
Two types of plastic are used for an electronics component. It is known that the breaking strengths (unit: psi) of plastic 1 and plastic 2 are normal with standard deviation \sigma_{1}=1.7 and \sigma_{2}=1.4 , respectively. Two random samples of sizes n_{1}=15 and n_{2}=12 are tested, and the sample means \overline{x}_{1}=170 and \overline{x}_{2}=164.5 . Construct a 95% upper confidence bound for the difference in the two population means μ₁ - H2.
Let 0.025 1.96, 0.05 =1.645, 0.025,25 =2.06, 10.05,25 =1.708
: 8
