Anjan wishes to test whether his mean journey time is different on Tuesdays. He chooses a random sample of 30 Tuesdays and finds that his mean journey time for these 30 Tuesdays is 40.2 minutes. Assume that the standard deviation for his journey time on Tuesdays is 6.9 minutes. The time, in minutes, for Anjan's journey to work on Mondays has mean $$$38.4$$$ and standard deviation $$$6.9$$$ State, with a reason, whether Anjan should use a one-tail or a two-tail test. ................................................................................................................................................ ................................................................................................................................................ ................................................................................................................................................ ................................................................................................................................................

Mathematics

IGCSE&ALevel

CAIE

Exam No：9709_w20_qp_63 Year：2020 Question No：6(b)(i)

Answer:

2-tail because looking for 'change', not decrease or increase

Knowledge points:

6.5.1 understand the nature of a hypothesis test, the difference between one-tailed and two-tailed tests, and the terms null hypothesis, alternative hypothesis, significance level, rejection region (or critical region), acceptance region and test statistic (Outcomes of hypothesis tests are expected to be interpreted in terms of the contexts in which questions are set.)

Answer:

Knowledge points:

Solution:

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