Answer:
The standard deviation of the age distribution is 6.2899 years.
Step-by-step explanation:
The formula to compute the standard deviation is:

The data provided is:
X = {19, 19, 21, 25, 25, 28, 29, 30, 31, 32, 40}
Compute the mean of the data as follows:

![=\frac{1}{11}\times [19+19+21+...+40]\\\\=\frac{299}{11}\\\\=27.182](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7B11%7D%5Ctimes%20%5B19%2B19%2B21%2B...%2B40%5D%5C%5C%5C%5C%3D%5Cfrac%7B299%7D%7B11%7D%5C%5C%5C%5C%3D27.182)
Compute the standard deviation as follows:

![=\sqrt{\frac{1}{11-1}\times [(19-27.182)^{2}+(19-27.182)^{2}+...+(40-27.182)^{2}]}}\\\\=\sqrt{\frac{395.6364}{10}}\\\\=6.28996\\\\\approx 6.2899](https://tex.z-dn.net/?f=%3D%5Csqrt%7B%5Cfrac%7B1%7D%7B11-1%7D%5Ctimes%20%5B%2819-27.182%29%5E%7B2%7D%2B%2819-27.182%29%5E%7B2%7D%2B...%2B%2840-27.182%29%5E%7B2%7D%5D%7D%7D%5C%5C%5C%5C%3D%5Csqrt%7B%5Cfrac%7B395.6364%7D%7B10%7D%7D%5C%5C%5C%5C%3D6.28996%5C%5C%5C%5C%5Capprox%206.2899)
Thus, the standard deviation of the age distribution is 6.2899 years.
Your question appears to be phrased incorrectly. If the ratio of soccer players to football players is 4:1 then for every 1 football player there are 4 soccer players. For example, if there are 3 football players, there would be 12 soccer players.
The equivalent expression would be S = 4F
The statement: "there are 4 more soccer players than football players" is not the same thing. It simply means that we add 4 to the total of football players to find out how many soccer players there are.
The equivalent expression would be S = F + 4
That being said: An equivalent ratio to 4:1 would be 8:2 , 12:3, 16:4, ...
Think of the ratio as a fraction. 4:1 = 4/1
4/1 = 8/2 = 12/3 = 16/4 ..., etc.
0.3% of 12,000 = 36 Correct ans