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
![\sigma=0.341](https://img.qammunity.org/2019/formulas/mathematics/college/rgrw4rb5fwjxq62qbi2k15ipqpv872tu5t.png)
The z score is given by this formula:
![z=(x-\mu)/(\sigma)](https://img.qammunity.org/2019/formulas/mathematics/college/u4ithhep47bpu4c0nca9bhq3gnmjzjkce5.png)
And for a time of 184.14 we have the following z score:
![z = (184.14-185.19)/(0.341)= -3.08](https://img.qammunity.org/2019/formulas/mathematics/college/agvost5dsr0jvnjrilapi33on9madbo6i5.png)
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
![\sigma=0.137](https://img.qammunity.org/2019/formulas/mathematics/college/et3dkyk4zxffdom0bfgme8nft1skclzaf0.png)
The z score is given by this formula:
![z=(x-\mu)/(\sigma)](https://img.qammunity.org/2019/formulas/mathematics/college/u4ithhep47bpu4c0nca9bhq3gnmjzjkce5.png)
And for a time of 110.05 we have the following z score:
![z = (110.05-110.4)/(0.137)=-2.557](https://img.qammunity.org/2019/formulas/mathematics/college/xz5p3h5sm4sd0qy34x3rc32vustyhdzqk5.png)
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.
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
![\sigma=0.341](https://img.qammunity.org/2019/formulas/mathematics/college/rgrw4rb5fwjxq62qbi2k15ipqpv872tu5t.png)
The z score is given by this formula:
![z=(x-\mu)/(\sigma)](https://img.qammunity.org/2019/formulas/mathematics/college/u4ithhep47bpu4c0nca9bhq3gnmjzjkce5.png)
And for a time of 184.14 we have the following z score:
![z = (184.14-185.19)/(0.341)= -3.08](https://img.qammunity.org/2019/formulas/mathematics/college/agvost5dsr0jvnjrilapi33on9madbo6i5.png)
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
![\sigma=0.137](https://img.qammunity.org/2019/formulas/mathematics/college/et3dkyk4zxffdom0bfgme8nft1skclzaf0.png)
The z score is given by this formula:
![z=(x-\mu)/(\sigma)](https://img.qammunity.org/2019/formulas/mathematics/college/u4ithhep47bpu4c0nca9bhq3gnmjzjkce5.png)
And for a time of 110.05 we have the following z score:
![z = (110.05-110.4)/(0.137)=-2.557](https://img.qammunity.org/2019/formulas/mathematics/college/xz5p3h5sm4sd0qy34x3rc32vustyhdzqk5.png)
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.