Answer:
Option A is correct.
The only unreasonable or not necessarily true conclusion about the wait times to ride a roller coaster that one can make is that: On one day, the lines were shorter than usual.
Explanation:
Which is an unreasonable conclusion about the wait times to ride the roller coaster?
Tracy is said to make a line plot of average wait times to ride the rollercoaster for days in one week.
So, the line plot is expected to have wait times for each day of the week plotted.
And we're told to examine a group of options to pick a conclusion that is unreasonable about the wait times to ride a roller coaster based on this line plot of average wait times per day for one week.
Taking each statement one at a time.
Statement A
On one day, the lines were shorter than usual.
Note that the line plot is of wait times, that is, time spent waiting in line is what is given, not the length of line. This means that, a short line doesn't necessarily equate to a small waiting time. As current roller coaster riders can take multiple rides, thereby increasing the wait times for potential riders even on a very short line.
Statement B
Riders can expect to wait about 10 minutes to ride the roller coaster.
This is a logical, reasonable conclusion as it is possible to obtain the average wait times for the whole week and approximate the average wait times.
Statement C
There was an outlier to the average wait times.
This is also a possible reasonable conclusion as an outlier would be very evident from such a plot.
Statement D
There is no way to make a reasonable prediction of the wait time.
It is also possible to obtain a very erratic distribution of wait times with values that are too far apart to make a reasonable prediction of wait time.
Hope this Helps!!!