Answer:
[tex]\displaystyle \bar x=4\ sec[/tex]
Step-by-step explanation:
Average Value
The mean or average of a number n of measurements is defined as the sum of all values divided by n.
[tex]\displaystyle \bar x=\frac{\sum x_i}{n}[/tex]
The running times in seconds are being improved by the following numbers:
5, 3, 4
This is the dataset where we have to find the mean value. Here n=3. Applying the formula:
[tex]\displaystyle \bar x=\frac{5+4+3}{3}[/tex]
[tex]\displaystyle \bar x=\frac{12}{3}[/tex]
[tex]\displaystyle \bar x=4\ sec[/tex]