Step 1 :Given the population mean \(\mu = 51400\), the level of significance \(\alpha = 0.05\), the sample mean \(\bar{x} = 50353\), the sample standard deviation \(s = 1600\), and the sample size \(n = 20\).
Step 2 :We first set up the null and alternative hypotheses. The null hypothesis \(H_0\) is that the population mean \(\mu\) is equal to 51400, and the alternative hypothesis \(H_a\) is that the population mean \(\mu\) is not equal to 51400. So, we have \(H_0: \mu = 51400\) and \(H_a: \mu \neq 51400\).
Step 3 :We then calculate the standardized test statistic, which is given by the formula \((\bar{x} - \mu) / (s / \sqrt{n})\). Substituting the given values, we get a test statistic of approximately -2.93.
Step 4 :We also need to find the critical value(s) for the t-distribution with \(n - 1 = 19\) degrees of freedom. For a two-tailed test with \(\alpha = 0.05\), the critical value(s) is(are) approximately 2.093.
Step 5 :\(\boxed{\text{Final Answer:}}\) The null and alternative hypotheses are \(H_0: \mu = 51400\) and \(H_a: \mu \neq 51400\). The value of the standardized test statistic is -2.93. The critical value(s) is(are) 2.093.