Maths Quest A Year 11 for Queensland WorkSHEET 11.1 Chapter 11 Scatterplots and time series WorkSHEET 11.1 1 Scatterplots and time series Name: ___________________________ 1 For each of the following determine which of the two variables would be the dependent variable. (a) tree height and age (b) flying time and aircraft speed (for given distance) (c) latitude and temperature (d) thickness of a book and its mass (e) size of a new car and its cost (a) (b) (c) (d) (e) tree height flying time temperature mass cost (a) (b) (c) (d) (e) increase decrease decrease increase increase 2 For each of the pairs of variables in question 1, indicate whether the second variable would increase or decrease in response to an increase in the value of the first variable. 3 For the graphs below, indicate whether the two variables graphed display a positive, negative (a) no relationship or no relationship between their values. (b) negative (c) positive Maths Quest A Year 11 for Queensland 4 Chapter 11 Scatterplots and time series The table below shows average monthly temperature and average occupancy rate of motel rooms in a rural locality. Average temperature (°C) Number of room nights occupied 25 20 30 18 12 6 7 8 18 20 23 26 45 40 50 47 40 28 20 16 25 30 48 50 (a) Which is the independent variable? (b) Draw a scatterplot of the data. Interpret the relationship between the two variables. (a) WorkSHEET 11.1 Average monthly temperature is the independent variable (put on the x-axis). (b) This shows moderate positive relationship between average monthly temperature and the number of room nights occupied. 2 Maths Quest A Year 11 for Queensland 5 Chapter 11 Scatterplots and time series The 10 a.m. temperature (°C) and rainfall (mm) over two weeks during the month of April in (a) Melbourne is shown below. Temperature (°C) Rainfall (mm) 5 3 16 5 20 8 10 9 14 6 8 7 18 8 13 7 9 6 17 7 7 4 14 10 4 2 3 1 (a) Which is the independent variable (put on the x-axis)? (b) Construct a scatterplot of rainfall against temperature. (b) WorkSHEET 11.1 Temperature is the independent variable (put on the x-axis). 3 Maths Quest A Year 11 for Queensland 6 Chapter 11 Scatterplots and time series This table shows the hearing test scores of people of different ages: Age 55.0 Hearing test score 2.5 40.0 3.8 35.0 4.0 30.0 3.9 42.0 2.5 48.0 3.2 50.0 2.2 48.0 1.8 32.0 3.0 45.0 2.0 30.0 4.0 56.0 1.8 (a) Which is the independent variable (put on the x-axis)? (b) Construct a scatterplot showing hearing test score against age. (a) (b) WorkSHEET 11.1 The independent variable is the age (put on the x-axis). 4 Maths Quest A Year 11 for Queensland 7 Chapter 11 Scatterplots and time series The heights and ulna (elbow to the centre of wrist bone) lengths of 15 Year-10 students from Clever High are shown below. (a) WorkSHEET 11.1 Ulna lengths is independent (put on the x-axis). (b) Ulna (cm) Heights (cm) 26 170 28 174 25 178 25 167 24 166 23 164 25 176 26 177 25 170 27 172 25 183 26 175 (a) Which measurement is independent (put on the x-axis)? (b) Construct a scatterplot of height against ulna lengths. (c) State the type of relationship between the two variables and draw a suitable conclusion. (c) The scatterplot shows weak positive relationship. There is evidence to suggest that as ulna length increases, the height also increases. 5 Maths Quest A Year 11 for Queensland 8 The table shows the number of Icy-poles sold and the maximum temperature of the day recorded by a shopkeeper. Maximum temperature 14 10 22 26 30 20 18 12 8 6 (a) (b) 9 Chapter 11 Scatterplots and time series Number of Icy-poles sold 250 200 365 500 630 420 320 280 220 150 (a) (b) Plot the data upon a scatterplot. State the type of relationship shown by the scatterplot and draw a suitable conclusion from it. The table below shows mass and height for men and women from 18 years upwards. Height (cm) Mass (kg) 150 50 160 57 170 65 180 72 190 81 200 90 (a) Construct a scatterplot showing this data. (b) State the type of relationship shown by the scatterplot and draw a suitable conclusion. WorkSHEET 11.1 3 The scatterplot shows moderate positive relationship. There is evidence to show that the higher the temperature, the higher the Icy-poles sales. (a) (b) 6 3 The scatterplot shows almost perfect positive relationship. Clearly, higher the height, higher the mass. Maths Quest A Year 11 for Queensland 10 Chapter 11 Scatterplots and time series A potato farmer records the yield in kilograms and the length in metres of 10 commercial potato plots as shown. WorkSHEET 11.1 (a) 3 Length (m) Yield (kg) 10 220 6 250 16 400 2 25 13 500 7 430 4 120 12 350 5 310 8 280 (a) Construct a scatterplot to illustrate this data. (b) State the type of relationship shown by the scatterplot and draw a suitable conclusion. (b) 7 The scatterplot shows positive relationship. There is evidence to show that as the length of the plot increases, the yield also increases.