Nacirema Airlines Is Buying A Fleet Of New Fuel-Efficient Pl

Nacirema Airlines Is Buying A Fleet Of New Fuel Efficient Planes The

Nacirema Airlines is purchasing a new fleet of fuel-efficient aircraft, specifically comparing the HogJet and the LitheJet models. Both planes satisfy their price and performance criteria, and both meet Environmental Protection Agency (EPA) noise guidelines. However, customer or company preferences lean toward choosing the quieter aircraft. To inform this decision, noise level tests are conducted during typical takeoff and landing sequences, repeated 10 times for each plane, with ground sensors recording the noise levels in decibels. The collected data are analyzed using a significance level of α = 0.05 to determine if there is a statistically significant difference in noise levels between the two aircraft. Given the research design and the analysis method, the primary question is whether the data support rejecting the null hypothesis (H0) in favor of the alternative hypothesis that one plane is quieter than the other.

Paper For Above instruction

The strategic decision by Nacirema Airlines to select the quieter aircraft model—either HogJet or LitheJet—relies heavily on statistical analysis of noise level data collected during repeated flight tests. The core question centers on whether the observed differences in noise levels are statistically significant, guiding the airline's choice in accordance with environmental standards, customer preferences, and operational needs.

In the context of hypothesis testing, the null hypothesis (H0) typically posits that there is no difference in mean noise levels between the two planes, i.e., µ_HogJet = µ_LitheJet. The alternative hypothesis (Ha), aligned with the airline’s preference for the quieter aircraft, is that the mean noise level of one plane is less than that of the other, expressed as µ_HogJet > µ_LitheJet or vice versa, depending on which aircraft is hypothesized to be quieter initially. Since the test involves assessing whether one plane is quieter, a left-tailed hypothesis test is appropriate if the alternative states the mean noise level of one aircraft is less than the other.

The data collected include repeated measures from 10 flights for each aircraft, with sensors recording decibel levels. Assuming normality in data distribution and equal variances, a paired or independent samples t-test is appropriate, depending on the experimental design. If the data indicate a statistically significant difference at α = 0.05, the null hypothesis should be rejected, leading the airline to favor the aircraft with significantly lower noise levels.

Given the statistical outputs from the tests—such as p-values—the decision rule is straightforward: if the p-value is less than α (0.05), reject H0; if not, fail to reject H0. Without specific numerical results in this scenario, the options are either to reject H0 if the evidence supports a significant difference or to not reject H0 when evidence is insufficient.

In this case, the test results indicate that, at the 5% significance level, there is either sufficient evidence to reject H0—implying a significant difference in noise levels favoring the quieter aircraft—or not. The provided options are: have insufficient information to make a decision, reject H0, or not reject H0. Since the analysis based on the summarized data leads to a conclusion that the evidence for a difference is not strong enough when the p-value exceeds 0.05, the correct choice would be "not reject H0" if the test results do not show significance.

Therefore, if the statistical test shows a p-value greater than 0.05, the appropriate conclusion is that there is not enough evidence to reject the null hypothesis, meaning that the data do not provide sufficient proof that one aircraft is quieter than the other at the specified significance level. Conversely, if the p-value were below 0.05, rejecting H0 would be appropriate, indicating a statistically significant difference favoring the quieter plane.

In summary, the decision hinges on the p-value derived from the statistical test. Based on the provided options and assuming the test results do not show a significant difference, the correct answer would be: not reject H0.

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