(Choose 1 answer)
(See picture)
A. (v)
B. (iii)
C. (ii)
D. (iv)
E. (i)
The burning rates of two different solid-fuel propellants used in aircrew escape systems are being studied. Assume that both populations are normally distributed, with standard deviation \sigma_{1}=3.5 centimeters per second and \sigma_{2}=4.2 centimeters per second for propellant 1 and propellant 2, respectively. Two random samples of n_{1}=25 and n_{2}=18 specimens are tested, the sample mean burning rates are \overline{x}_{1}=28.1 centimeters per second and \overline{x_{2}}=27.5 centimeters per second. A researcher would like to test the hypothesis that both propellants have the same mean burning rate, at the 5% significance level. State the null and alternative hypotheses and find the value of the test statistic =0.
8
(ⅰ H_{n}:\mu-\mu_{1}=0,H,:\mu-\mu_{1}e0,z_{n}=0.98;
