- In this question you must show all stages of your working. Solutions relying entirely on calculator technology are not acceptable.
A software developer released an app to download.
The numbers of downloads of the app each month, in thousands, for the first three months after the app was released were
$$2 k - 15 \quad k \quad k + 4$$
where \(k\) is a constant.
Given that the numbers of downloads each month are modelled as a geometric series,
- show that \(k ^ { 2 } - 7 k - 60 = 0\)
- predict the number of downloads in the 4th month.
The total number of all downloads of the app is predicted to exceed 3 million for the first time in the \(N\) th month.
- Calculate the value of \(N\) according to the model.