We will have the following:
First, we determine the slope of the linear relationship:
![m=(320-380)/(2.75-2.5)\Rightarrow m=-240](https://img.qammunity.org/2023/formulas/mathematics/college/iwopmduu0tslg1zfvdud6eiad047evb8fn.png)
a) Now, using this information and one point (2.50, 380) we will replace in the general equation for a linear function, that is:
![\begin{gathered} N(p)-y_1=m(p-x_1)\Rightarrow N(p)-380=-240(p-2.5) \\ \\ \Rightarrow N(p)-380=-240p+600 \\ \\ \Rightarrow N(p)=-240p+980 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ffp7iz5xsflj2pya7n42m2cjmjlo5hcquv.png)
So, the equation is:
![N(p)=-240p+980](https://img.qammunity.org/2023/formulas/mathematics/college/vx9zhbwrlub4bof31rru1itg1nd18h06jt.png)
b) We determine the revenue function as follows:
![\begin{gathered} R(p)=pN(p)\Rightarrow R(p)=p(-240p+980) \\ \\ \Rightarrow R(p)=-240p^2+980p \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/k1ephx6f8iilc38ad9oc0fyj2qm2glbmae.png)
So, the equation of revenue is:
![R(p)=-240p^2+980p](https://img.qammunity.org/2023/formulas/mathematics/college/37v3owoelv0e0y3psmlpjbn3qiov0pcdo9.png)
c) We determine the critical points of the revenue:
![\begin{gathered} R^(\prime)(p)=-480p+980=0\Rightarrow480p=980 \\ \\ \Rightarrow p=(49)/(24)\Rightarrow p\approx2.04 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/e1g2fqabv44sprv8aap4l19vntp8y9jqbg.png)
So, the price that maximizes revenue is approximately $2.04.
The maximum revenue will be:
![\begin{gathered} R(2.04)=-240(2.04)^2+980(2.04)\Rightarrow R(2.04)=1000.416... \\ \\ \Rightarrow R(2.04)\approx1000.42 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/lryytkeeyeb1ihuz93u2exinari01yss24.png)
So, the maximum revenue is approximately $1000.42.