Question
Six students revise for a test.
The scatter diagram shows the time, in hours, each student spent revising and their mark in the test.
(a) The data for two more students is shown in the table.
Plot these two points on the scatter diagram.
(b) What type of correlation is shown on the scatter diagram?
(c) Draw a line of best fit on the scatter diagram.
(d) Another student spent 5.5 hours revising.
Estimate a mark for this student.
Answer/Explanation
Ans:
(a) Points plotted at (4.5, 33) and (6.5, 35)
(b) Positive
(c) Correct ruled line
(d) 33.5 to 37.5
Question
A travel brochure has 72 holidays in four different countries.
The pie chart shows this information.
(a) There are 24 holidays in Thailand.
Show that the sector angle for Thailand is 120°.
Answer/Explanation
Ans: correct working
(b) The sector angle for Malaysia is 150°.
The sector angle for Singapore is twice the sector angle for Hong Kong.
Calculate the number of holidays in Hong Kong.
Answer/Explanation
Ans: 6 nfww
Question
40 people were asked how many times they visited the cinema in one month.
The table shows the results.
(a) (i) Find the mode.
……………………………………….
(ii) Calculate the mean.
………………………………………
(b) Omar wants to show the information from the table in a pie chart.
Calculate the sector angle for the people who visited the cinema 5 times.
……………………………………….
Answer/Explanation
(a)(i) 4
(a)(ii) 3.2
(b)27
Question
Aisha records the distance she runs and her average speed.
The results are shown in the scatter diagram.
(a) The table shows the results of four more runs.
On the scatter diagram, plot these points.
(b) What type of correlation is shown in the scatter diagram?
………………………………………….
(c) On the scatter diagram, draw a line of best fit.
(d) Use your line of best fit to estimate her average speed when she runs a distance of 6km.
…………………………………. km/h
Answer/Explanation
(a) 4 points correctly plotted
(b) Negative
(c) Correct ruled line of best fit
(d) 10 to 12
Question
Mrs Salaman gives her class two mathematics tests.
The scatter diagram shows information about the marks each student scored
(a) Write down the highest mark scored on test 1.
………………………………………….
(b) Write down the type of correlation shown in the scatter diagram.
………………………………………….
(c) Draw a line of best fit on the scatter diagram.
(d) Hamish scored a mark of 40 on test 1.
He was absent for test 2.
Use your line of best fit to find an estimate for his mark on test 2.
………………………………………….
Answer/Explanation
(a)66
(b)Positive
(c) Ruled line of best fit
(d) 46 to 50
Question
The number of passengers on a bus is recorded each day for 14 days.
15 18 22 17 35 38 24
19 19 24 25 31 36 29
(a) Complete the stem-and-leaf diagram.
(b) Find the median.
………………………………………….
Answer/Explanation
(a)
(b)24
Question
The scatter diagram shows the marks obtained in a Mathematics test and the marks obtained in an
English test by 15 students.
(a) Describe the correlation.
(b) The mean for the Mathematics test is 47.3 .
The mean for the English test is 30.3 .
Plot the mean point (47.3, 30.3) on the scatter diagram above.
(c) (i) Draw the line of best fit on the diagram above.
(ii) One student missed the English test.
She received 45 marks in the Mathematics test.
Use your line to estimate the mark she might have gained in the English test.
Answer/Explanation
(a) Negative correlation