Answer:
The correct option is;
C. This advanced training seminar did not reduce response time, t(35) = -1.43, p > 0.05
Step-by-step explanation:
The given parameters are;
The population mean response time, μ = 9 minutes
The number of police officers in the sample, n = 36
The mean response time after the training, [tex]\overline x[/tex] = 8 minutes
The standard deviation of the response time after the training, s = 4.2 minutes
The level of significance, α = 0.05
The null hypothesis; μ ≥ 9
The alternative hypothesis; μ < 9
The test statistic for the t-test is [tex]t=\dfrac{\bar{x}-\mu }{\dfrac{s}{\sqrt{n}}}[/tex], therefore, we get;
[tex]t=\dfrac{8-9 }{\dfrac{4.2}{\sqrt{36}}} \approx -1.42857142857[/tex]
The degrees of freedom, df = n - 1 = 36 - 1 = 35
The critical-t at 0.05 level of significance is critical-t = 1.69, p(t < -1.43) > 0.05
and, we fail to reject the null hypothesis, therefore, the advanced training did not reduce the response time
