Answer:
79. [7, 12], [1, 6]
80. The total revenue in the month of May is $11,575
81. The total revenue in the month of November is $4,630
82. Values obtained from the model and actual values are almost the same, so the given model is precise.
Step-by-step explanation:
79.
The domain of a function is the set of x-values that we are allowed to plug into our function.
The graph below represents f(x),
the graph that the domain of the first part of the function is [7,12]. The domain of the second part of the function is [1,6]. The solution is:
[tex]f(x)=\left \{ {{-1.97x+26.3, 7 \leq x \leq 12} \atop {0.505x^{2} -1.47x+6.3, 1 \leq x \leq 6}} \right. \\\\[/tex]
80.
1 ≤ 5 ≤ 6, so we'll plug the value 5 in the function f(x) = 0.505x² - 1.47x + 6.3
f(x) = y = (0.505)(5)² - 1.47(5) + 6.3
f(x) = y = (0.505)(25) - 7.35 + 6.3
f(x) = y = 12.625 - 1.05
f(x) = y = 11.575
For x=5 which represents 5th month May, we got y=11.575
Therefore, the total revenue in the month of May is 11.575 thousands dollars, ie 11,575 dollars.
81.
7 ≤ 11 ≤ 12, so we'll plug the value 11 in the function f(x) = -1.97x + 26.3
f(x) = − 1.97(11) + 26.3
= − 21.67 + 26.3
= 4.630.
For x=11 which represents 11th month November, we got y=4.630 Therefore, the total revenue in the month of November is 4.630 thousands dollars, 4,630 dollars.
82.
Values obtained from the model are y=11.575 (x=5) and y=4.630 (x=11). Actual data values are y=11.5 (x=5) and y=4.4 (x=11)
By comparing these values, we can conclude that the model is precise, because these values are almost the same.
Learn more about Piecewise Functions here: https://brainly.com/question/13882670
