(b) a researcher discovers that between 2008 and 2010, the number of 13] messages sent on twitter (called tweets) increased exponentially. she investigates the number of tweets from a popular author, and finds that they can be modelled by the equation 20 x (1.8)', u where u is the total number of tweets sent, and t is the number of months since the author became a twitter user, where 0 ts 8. (i) copy and complete the table below, giving the total mumber of tweets sent (rounding to the nearest whole number). number of months since total number registering as a twitter user of tweets sent use the method shown in unit 13, subsection 5.2 to find the month in which the exponential model predicts that the total number of tweets sent will first reach 500. (ii) (ii) write down the value of the scale factor for the exponential model. use this to find the percentage increase in the total number of tweets each month page 9 of 10