It would be B - 30° celcus. Because when you convert 86° into celcus it becomes 30°. I hoped this helped!
Daniela made her error on step 3 because it says:
"Find the ratio of the differences of the means compared to the mean absolute deviation.
She didn't find the difference between the today and last week means. She just put the mean as a whole.
I'll give a practice problem to help explain it a bit better.
Here, let's try to solve 45% of of 60.
First, we convert the percentage into a decimal. To turn any percentage into a decimal you move the point two spaces to the left.
That means 45% as a decimal is .45.
Next, we multiply our number, 60, by the decimal .45.
60×.45=27.
That means 45% of 60 is 27.
To sum it all up, you have to get the percentage, move the decimal point two spaces to the left, and multiply it by the number you were trying to find the percentage of.
Have a wonderful day! :)
If a is the number of events, then a = 1. Plugging in 1 for a in the equation

, you get

.
Total cost is $9.