CAIE S1 2010 November — Question 5 8 marks

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2010
SessionNovember
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicData representation
TypeComplete frequency table from histogram only
DifficultyModerate -0.8 This is a routine histogram interpretation question requiring students to apply the formula frequency = frequency density × class width, then calculate a mean from grouped data and a basic probability. These are standard S1 techniques with no problem-solving insight required, making it easier than average but not trivial due to the multi-step nature and potential for arithmetic errors.
Spec2.02a Interpret single variable data: tables and diagrams2.02b Histogram: area represents frequency2.02g Calculate mean and standard deviation2.04b Binomial distribution: as model B(n,p)2.04c Calculate binomial probabilities

5 The following histogram illustrates the distribution of times, in minutes, that some students spent taking a shower. \includegraphics[max width=\textwidth, alt={}, center]{ec425eaf-8afc-4671-9ef3-ba2477b884ef-3_1031_1326_372_406}
  1. Copy and complete the following frequency table for the data.
    Time \(( t\) minutes \()\)\(2 < t \leqslant 4\)\(4 < t \leqslant 6\)\(6 < t \leqslant 7\)\(7 < t \leqslant 8\)\(8 < t \leqslant 10\)\(10 < t \leqslant 16\)
    Frequency
  2. Calculate an estimate of the mean time to take a shower.
  3. Two of these students are chosen at random. Find the probability that exactly one takes between 7 and 10 minutes to take a shower.

5 The following histogram illustrates the distribution of times, in minutes, that some students spent taking a shower.\\
\includegraphics[max width=\textwidth, alt={}, center]{ec425eaf-8afc-4671-9ef3-ba2477b884ef-3_1031_1326_372_406}\\
(i) Copy and complete the following frequency table for the data.

\begin{center}
\begin{tabular}{ | l | l | l | l | l | l | l | }
\hline
Time $( t$ minutes $)$ & $2 < t \leqslant 4$ & $4 < t \leqslant 6$ & $6 < t \leqslant 7$ & $7 < t \leqslant 8$ & $8 < t \leqslant 10$ & $10 < t \leqslant 16$ \\
\hline
Frequency &  &  &  &  &  &  \\
\hline
\end{tabular}
\end{center}

(ii) Calculate an estimate of the mean time to take a shower.\\
(iii) Two of these students are chosen at random. Find the probability that exactly one takes between 7 and 10 minutes to take a shower.

\hfill \mbox{\textit{CAIE S1 2010 Q5 [8]}}