Standard +0.8 This is a reverse normal distribution problem requiring students to use inverse standardization with two percentiles to set up simultaneous equations for μ and σ. While the method is standard S1 content, it involves multiple steps (finding z-scores from tables, setting up two equations, solving simultaneously) and careful algebraic manipulation, making it moderately harder than typical single-percentile problems.
A group of students believes that the time taken to travel to college, \(T\) minutes, can be assumed to be normally distributed. Within the college 5\% of students take at least 55 minutes to travel to college and 0.1\% take less than 10 minutes.
Find the mean and standard deviation of \(T\).
[9]
A group of students believes that the time taken to travel to college, $T$ minutes, can be assumed to be normally distributed. Within the college 5\% of students take at least 55 minutes to travel to college and 0.1\% take less than 10 minutes.
Find the mean and standard deviation of $T$.
[9]
\hfill \mbox{\textit{Edexcel S1 Q2 [9]}}