AQA S2 2008 January — Question 1 6 marks

Exam BoardAQA
ModuleS2 (Statistics 2)
Year2008
SessionJanuary
Marks6
PaperDownload PDF ↗
TopicZ-tests (known variance)
TypeOne-tail z-test (upper tail)
DifficultyModerate -0.3 This is a straightforward one-sample hypothesis test with all values provided and a standard procedure to follow. While it requires correct identification of hypotheses, calculation of a test statistic, and comparison to critical value, these are routine S2 techniques with no conceptual subtleties or multi-step problem-solving required.
Spec5.05c Hypothesis test: normal distribution for population mean

1 David claims that customers have to queue at a supermarket checkout for more than 5 minutes, on average. The queuing times, \(x\) minutes, of 40 randomly selected customers result in \(\bar { x } = 5.5\) and \(s ^ { 2 } = 1.31\). Investigate, at the \(1 \%\) level of significance, David's claim.

1 David claims that customers have to queue at a supermarket checkout for more than 5 minutes, on average.

The queuing times, $x$ minutes, of 40 randomly selected customers result in $\bar { x } = 5.5$ and $s ^ { 2 } = 1.31$.

Investigate, at the $1 \%$ level of significance, David's claim.

\hfill \mbox{\textit{AQA S2 2008 Q1 [6]}}