By finding the minimum of the given function, we conclude that the lowest average temperature that year is 57°F.
We know that the average temperature is given by the equation:
f(x)=31cos(0.0055πx)+88
And it is in Fahrenheit degrees.
To get the lowest average temperature, we just need to find the minimum of the above function.
Remember that the minimum of the cosine function is:
cos(x) = -1
Then the lowest value of the above function is:
f(x₀) = 31*(-1) + 88 = 57
From this, we conclude that the lowest average temperature that year is 57°F, so the correct option is A.
If you want to learn more about cosine functions:
https://brainly.com/question/8120556
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