Moderate -0.8 This is a straightforward binomial approximation question requiring only standard technique: identify parameters (n=60, p=0.35), apply normal approximation with continuity correction, standardize, and look up the value. The setup is simple with no conceptual challenges, making it easier than average but not trivial due to the multi-step calculation required for 6 marks.
In a large town, 35% of the inhabitants have access to television channel \(C\). A random sample of 60 inhabitants is obtained. Use a suitable approximation to find the probability that 18 or fewer inhabitants in the sample have access to channel \(C\). [6]
In a large town, 35% of the inhabitants have access to television channel $C$. A random sample of 60 inhabitants is obtained. Use a suitable approximation to find the probability that 18 or fewer inhabitants in the sample have access to channel $C$. [6]
\hfill \mbox{\textit{OCR S2 2010 Q3 [6]}}