Answer:
(a)
![D(x)=-2,500x+60,000](https://img.qammunity.org/2021/formulas/mathematics/college/y4pcdc4ihz1thibw7hdhsg4s35nwuyds6z.png)
(b)
![R(x)=60,000x-2500x^2](https://img.qammunity.org/2021/formulas/mathematics/college/t06x24h4o5ff8pwnzg295jxjwfvy7l2ouk.png)
(c) x=12
(d)Optimal ticket price: $12
Maximum Revenue:$360,000
Explanation:
The stadium holds up to 50,000 spectators.
When ticket prices were set at $12, the average attendance was 30,000.
When the ticket prices were on sale for $10, the average attendance was 35,000.
(a)The number of people that will buy tickets when they are priced at x dollars per ticket = D(x)
Since D(x) is a linear function of the form y=mx+b, we first find the slope using the points (12,30000) and (10,35000).
![\text{Slope, m}=(30000-35000)/(12-10)=-2500](https://img.qammunity.org/2021/formulas/mathematics/college/hxgh5mdvkeakhzssobhkwclmdzez8lqrkq.png)
Therefore, we have:
![y=-2500x+b](https://img.qammunity.org/2021/formulas/mathematics/college/1m13mybsfbw28qo3lirvdy04h5mtpbo4f9.png)
At point (12,30000)
![30000=-2500(12)+b\\b=30000+30000\\b=60000](https://img.qammunity.org/2021/formulas/mathematics/college/n4nsnw11jwri65up6njc4a7ij38p77asaj.png)
Therefore:
![D(x)=-2,500x+60,000](https://img.qammunity.org/2021/formulas/mathematics/college/y4pcdc4ihz1thibw7hdhsg4s35nwuyds6z.png)
(b)Revenue
![R(x)=x \cdot D(x) \implies R(x)=x(-2,500x+60,000)\\\\R(x)=60,000x-2500x^2](https://img.qammunity.org/2021/formulas/mathematics/college/xx32gwoo317z3jqkic19mmh36znhwkywqw.png)
(c)To find the critical values for R(x), we take the derivative and solve by setting it equal to zero.
![R(x)=60,000x-2500x^2\\R'(x)=60,000-5,000x\\60,000-5,000x=0\\60,000=5,000x\\x=12](https://img.qammunity.org/2021/formulas/mathematics/college/hv4i7l28tm1cyt2m4vxl55py7glh7dvo0p.png)
The critical value of R(x) is x=12.
(d)If the possible range of ticket prices (in dollars) is given by the interval [1,24]
Using the closed interval method, we evaluate R(x) at x=1, 12 and 24.
![R(x)=60,000x-2500x^2\\R(1)=60,000(1)-2500(1)^2=\$57,500\\R(12)=60,000(12)-2500(12)^2=\$360,000\\R(24)=60,000(24)-2500(24)^2=\$0](https://img.qammunity.org/2021/formulas/mathematics/college/nw7gifpj0qs1dvlb4s16v66xqfrf72yz4f.png)
Therefore:
- Optimal ticket price:$12
- Maximum Revenue:$360,000