- A random sample of 15 days is taken from the large data set for Perth in June and July 1987. The scatter diagram in Figure 1 displays the values of two of the variables for these 15 days.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{2b63aa7f-bc50-4422-8dc0-e661b521c221-04_722_709_376_677}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{figure}
- Describe the correlation.
The variable on the \(x\)-axis is Daily Mean Temperature measured in \({ } ^ { \circ } \mathrm { C }\).
- Using your knowledge of the large data set,
- suggest which variable is on the \(y\)-axis,
- state the units that are used in the large data set for this variable.
Stav believes that there is a correlation between Daily Total Sunshine and Daily Maximum Relative Humidity at Heathrow.
He calculates the product moment correlation coefficient between these two variables for a random sample of 30 days and obtains \(r = - 0.377\)
- Carry out a suitable test to investigate Stav's belief at a \(5 \%\) level of significance. State clearly
- your hypotheses
- your critical value
On a random day at Heathrow the Daily Maximum Relative Humidity was 97\% - Comment on the number of hours of sunshine you would expect on that day, giving a reason for your answer.