Datcb565 Competency 2 Assessment

Call Time Analysis Note: The decision for each hypothesis test is either reject Ho or fail to reject Ho. Time in Queue Test The team performed a test of hypothesis to determine whether the average TiQ is lower than the industry standard of 2.5 minutes (150 seconds). A significance level α = 0.05 was used. This is a one-tailed test of mean against a hypothesized value of 150 seconds. Because the sample size was large, we assumed knowledge of the population’s variance. The null and alternate hypotheses is: Ho : µ ≥ 150 H1 : µ < 150 This is a left-tailed test, and with a significance level of α = 0.05 the critical value is z = -1.645. The decision rule becomes: Reject Ho if zcalc < -1.645. Figure 1: TiQ Rejection Region The test statistic is given by: z_calc=(x ̅-μ_o)/(σ⁄√n)=(147.9-150)/(138.0⁄√1674)=(-2.1)/3.37=-0.62 The test statistic zcalc falls outside the rejection region, so we fail to reject the null hypothesis. There is not enough evidence to conclude that the call center’s average TiQ is lower than the industry standard of 150 seconds. Figure 2: Results of TiQ Hypothesis Test: Mean versus Hypothesized Value Average Service Time Test The team performed a test of hypothesis to determine whether the service time (ST) with new service protocol PE is lower than with the current protocol PT. A significance level of α=0.05 was used. This is a test of means for two independent samples with unknown variances assumed unequal. Sample 1 is the data from the protocol PT. Sample 2 is the data from the protocol PE. We tested whether the mean ST with protocol PE is smaller than the mean with protocol PT. μ_PT = mean ST under the traditional protocol PT (sample 1) μ_PE = mean ST under the new protocol PE (sample 2) Research question: Is μ_PE < μ_PT ?