Answer:
C. Team Y’s scores have a lower mean value.
Step-by-step explanation:
We are given that Two soccer teams play 8 games in their season. The number of goals each team scored per game is listed below:
Team X: 11, 3, 0, 0, 2, 0, 6, 4
Team Y: 4, 2, 0, 3, 2, 1, 6, 4
Firstly, we will calculate the mean, median, range and inter-quartile range for Team X;
Mean of Team X data is given by the following formula;
Mean,
=
=
=
= 3.25
So, the mean of Team X's scores is 3.25.
Now, for calculating the median; we have to arrange the data in ascending order and then observe that the number of observations (n) in the data is even or odd.
Team X: 0, 0, 0, 2, 3, 4, 6, 11
- If n is odd, then the formula for calculating median is given by;
Median = 
- If n is even, then the formula for calculating median is given by;
Median =
Here, the number of observations is even, i.e. n = 8.
So, Median =
= 
= 
=
= 2.5
So, the median of Team X's score is 2.5.
Now, the range is calculated as the difference between the highest and the lowest value in our data.
Range = Highest value - Lowest value
= 11 - 0 = 11
So, the range of Team X's score is 11.
Now, the inter-quartile range of the data is given by;
Inter-quartile range = 

= 
= 
![Q_1 = 2^{nd} \text{ obs.} + 0.25[ 3^{rd} \text{ obs.} -2^{nd} \text{ obs.} ]](https://tex.z-dn.net/?f=Q_1%20%3D%202%5E%7Bnd%7D%20%5Ctext%7B%20obs.%7D%20%2B%200.25%5B%203%5E%7Brd%7D%20%5Ctext%7B%20obs.%7D%20-2%5E%7Bnd%7D%20%5Ctext%7B%20obs.%7D%20%5D)
= 0 + 0.25[0 - 0] = 0

= 
= 
![Q_3 = 6^{th} \text{ obs.} + 0.75[ 7^{th} \text{ obs.} -6^{th} \text{ obs.} ]](https://tex.z-dn.net/?f=Q_3%20%3D%206%5E%7Bth%7D%20%5Ctext%7B%20obs.%7D%20%2B%200.75%5B%207%5E%7Bth%7D%20%5Ctext%7B%20obs.%7D%20-6%5E%7Bth%7D%20%5Ctext%7B%20obs.%7D%20%5D)
= 4 + 0.75[6 - 4] = 5.5
So, the inter-quartile range of Team X's score is (5.5 - 0) = 5.5.
<u>Now, we will calculate the mean, median, range and inter-quartile range for Team Y;</u>
Mean of Team Y data is given by the following formula;
Mean,
=
=
=
= 2.75
So, the mean of Team Y's scores is 2.75.
Now, for calculating the median; we have to arrange the data in ascending order and then observe that the number of observations (n) in the data is even or odd.
Team Y: 0, 1, 2, 2, 3, 4, 4, 6
- If n is odd, then the formula for calculating median is given by;
Median = 
- If n is even, then the formula for calculating median is given by;
Median =
Here, the number of observations is even, i.e. n = 8.
So, Median =
= 
= 
=
= 2.5
So, the median of Team Y's score is 2.5.
Now, the range is calculated as the difference between the highest and the lowest value in our data.
Range = Highest value - Lowest value
= 6 - 0 = 6
So, the range of Team Y's score is 6.
Now, the inter-quartile range of the data is given by;
Inter-quartile range = 

= 
= 
![Q_1 = 2^{nd} \text{ obs.} + 0.25[ 3^{rd} \text{ obs.} -2^{nd} \text{ obs.} ]](https://tex.z-dn.net/?f=Q_1%20%3D%202%5E%7Bnd%7D%20%5Ctext%7B%20obs.%7D%20%2B%200.25%5B%203%5E%7Brd%7D%20%5Ctext%7B%20obs.%7D%20-2%5E%7Bnd%7D%20%5Ctext%7B%20obs.%7D%20%5D)
= 1 + 0.25[2 - 1] = 1.25

= 
= 
![Q_3 = 6^{th} \text{ obs.} + 0.75[ 7^{th} \text{ obs.} -6^{th} \text{ obs.} ]](https://tex.z-dn.net/?f=Q_3%20%3D%206%5E%7Bth%7D%20%5Ctext%7B%20obs.%7D%20%2B%200.75%5B%207%5E%7Bth%7D%20%5Ctext%7B%20obs.%7D%20-6%5E%7Bth%7D%20%5Ctext%7B%20obs.%7D%20%5D)
= 4 + 0.75[4 - 4] = 4
So, the inter-quartile range of Team Y's score is (4 - 1.25) = 2.75.
Hence, the correct statement is:
C. Team Y’s scores have a lower mean value.