Answer:
Let X the random variable that represent the mean finish time for a yearly amateur auto race a population, and for this case we know the distribution for X is given by:
Where
and 
The z score is given by this formula:

And for a time of 184.14 we have the following z score:

Let Y the random variable that represent the mean finish time for the previous year auto race a population, and for this case we know the distribution for X is given by:
Where
and 
The z score is given by this formula:

And for a time of 110.05 we have the following z score:

As we can see we have a higher z score for the case of the previous year so then we have a more convincing victory on this case since represent a higher quantile in the normal standard distribution.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the mean finish time for a yearly amateur auto race a population, and for this case we know the distribution for X is given by:
Where
and 
The z score is given by this formula:

And for a time of 184.14 we have the following z score:

Let Y the random variable that represent the mean finish time for the previous year auto race a population, and for this case we know the distribution for X is given by:
Where
and 
The z score is given by this formula:

And for a time of 110.05 we have the following z score:

As we can see we have a higher z score for the case of the previous year so then we have a more convincing victory on this case since represent a higher quantile in the normal standard distribution.