SOLUTION
Since the number of bacterial increases then this shows an exponential growth function:
The function is defined as
![y=a(1+r)^x](https://img.qammunity.org/2023/formulas/mathematics/college/zju8ii5bf2piwkg7euivlsfo19d8ktxf14.png)
The initial value is 113 and the rate is 82% hence the equation becomes
![\begin{gathered} y=113(1+82\%)^x \\ y=113(1+0.82)^x \\ y=113(1.82)^x \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/g1pamseyh92ssty091ces2o2oypz3nsz79.png)
Therefore the equation is of the form
![y=113(1.82)^x](https://img.qammunity.org/2023/formulas/mathematics/college/qz91av9kwmqzpv6bdvzeilex2qkicb1x1e.png)
To find the number of bacteria after 7 days substitute x=7 into the equation
This gives
![\begin{gathered} y=113(1.82)^7 \\ y=7474.43 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1l18hh8mskjquphygmjy55udd223499fmy.png)
Therefore the value of y is
![y=7474.43](https://img.qammunity.org/2023/formulas/mathematics/college/ite5e97c86t27khput46338cm7sd8glaio.png)