Standard +0.3 This is a straightforward paired t-test application with clear hypotheses (one-tailed test for μ_d > 0). Students must calculate the test statistic from summary statistics and compare to critical value, but it's a standard S4 procedure requiring no novel insight—slightly easier than average due to being a textbook application of a core technique.
A doctor believes that the span of a person's dominant hand is greater than that of the weaker hand. To test his theory, the doctor measures the spans of the dominant and weaker hands of a random sample of 8 people. He subtracts the span of the weaker hand from that of the dominant hand. The spans, in cm, are summarised in the table below.
\includegraphics{figure_4}
Test, at the 5\% significance level, the doctor's belief. [9]
A doctor believes that the span of a person's dominant hand is greater than that of the weaker hand. To test his theory, the doctor measures the spans of the dominant and weaker hands of a random sample of 8 people. He subtracts the span of the weaker hand from that of the dominant hand. The spans, in cm, are summarised in the table below.
\includegraphics{figure_4}
Test, at the 5\% significance level, the doctor's belief. [9]
\hfill \mbox{\textit{Edexcel S4 Q4 [9]}}