Question

the list gives the speeds, in miles per hour, of 7 serves made by a professional tennis player. 104, 109, 109, 111, 152, 155, 156. what is the mean speed, in miles per hour, of these 7 serves? a 156 b 128 c 111 d 109

Explanation:

1. Discipline and Sub - field:

• The problem is about calculating the mean of a set of data values. This falls under the discipline of Mathematics, specifically the sub - field of Statistics.

1. Calculation of the mean:

• The mean \(\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}\), where \(x_{i}\) are the data points and \(n\) is the number of data points.
• The data set is \(104,109,109,111,152,155,156\).
• \(\sum_{i=1}^{7}x_{i}=104 + 109+109+111+152+155+156=896\).
• \(n = 7\).
• \(\bar{x}=\frac{896}{7}=128\).

Answer:

B. 128