(b) The same teacher decides to look into rates of asthma, having seen a box full of inhalers at school. She nds that the number of admissions to hospital for asthma can be modelled by the equation y : 0.88 x (1.06)t (3 s t S 65) where y is the number of asthma admissions to hospital per 1000 children (globally) and t is the number of years since the start of 1955. (i) Which type of growth is this an example of: linear or exponential? Describe how growth rate differs between linear and exponential functions. (ii) Calculate the number of asthma admissions to hospital per 1000 children at the start of the year 1970, according to this model. (iii) Write down the scale factor and use this to nd the percentage increase in the number of asthma admissions to hospital per 1000 children per year. (iv) Use the method shown in Subsection 5.2 of Unit 13 to nd the year in which the number of asthma admissions to hospital per 1000 children exceeded 4