Final Answer:
The average score on the original model f(t)=90-15log(t+1), 0<=t<=12, was approximately 55.84.
Step-by-step explanation:
The average of a function over an interval [a, b] is calculated using the formula:
![\[ \bar{f} = (1)/(b - a) \int_(a)^(b) f(t) \, dt \]](https://img.qammunity.org/2024/formulas/mathematics/college/idkt1tf2t879jtmr5f3akzcgud4j8mk5b5.png)
In this case, the function is
and the interval is [0, 12]. So, the average score is given by:
![\[ \bar{f} = (1)/(12 - 0) \int_(0)^(12) (90 - 15 \log(t+1)) \, dt \]](https://img.qammunity.org/2024/formulas/mathematics/college/2x26gpdxev9yr4gxf71fkf1lel9qu9mj1m.png)
To evaluate the integral, we can use the antiderivative of
, which is:
![\[ F(t) = 90t - 15(t \log(t+1) - t) \]](https://img.qammunity.org/2024/formulas/mathematics/college/g8yl9x45wxv31l1blp6hvxmgdenagtg5re.png)
Now, applying the fundamental theorem of calculus, we have:
![\[ \bar{f} = (1)/(12 - 0) [F(12) - F(0)] \]](https://img.qammunity.org/2024/formulas/mathematics/college/afqlnxncqqg00gdagoa93y4m6wwpfddfgx.png)
After substituting the values, we get:
![\[ \bar{f} = (1)/(12) [(90 \cdot 12 - 15(12 \log(13) - 12)) - (90 \cdot 0 - 15(0 \log(1) - 0))] \]](https://img.qammunity.org/2024/formulas/mathematics/college/poueber2q9gcqgu2nu7ivo08lqt693c8r7.png)
Solving this expression yields the final result of approximately 55.84.
In summary, the average score on the original model over the interval [0, 12] is 55.84. This calculation involves finding the antiderivative of the function and applying the fundamental theorem of calculus to evaluate the average value over the given interval.