Photo AI
A random sample of 15 days is taken from the large data set for Perth in June and July 1987 - Edexcel - A-Level Maths Statistics - Question 2 - 2020 - Paper 1
Question 2
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 varia... show full transcript
Worked Solution & Example Answer:A random sample of 15 days is taken from the large data set for Perth in June and July 1987 - Edexcel - A-Level Maths Statistics - Question 2 - 2020 - Paper 1
Step 1
Describe the correlation.
Answer
The scatter plot indicates a negative correlation between the Daily Mean Temperature and the variable on the y-axis. This is evidenced by the downward slope of the plotted points, suggesting that as the temperature increases, the second variable tends to decrease.
Step 2
Step 3
Step 4
Carry out a suitable test to investigate Stav's belief at a 5% level of significance. State clearly your hypotheses.
Answer
The null hypothesis (H0): There is no correlation between Daily Total Sunshine and Daily Maximum Relative Humidity. The alternative hypothesis (H1): There is a correlation between Daily Total Sunshine and Daily Maximum Relative Humidity.
To find the critical value, we use a correlation significance table for a sample size of 30 days at a 5% significance level. The critical value is -0.361.
Step 5
Step 6
Comment on the number of hours of sunshine you would expect on that day, justifying your answer.
Answer
Given that on the random day at Heathrow the Daily Maximum Relative Humidity was 97%, it can be expected that the number of hours of sunshine would be lower than average. This is because high humidity typically correlates with cloudy conditions, which reduce sunlight exposure.