A student reported following arsenic concentrations in water samples:
$$\begin{array}{|l|l|l|l|l|l|l|l|}\hline \text{Arsenic concentration (mg/L)} & 0.10 & 0.12 & 0.20 & 0.05 & 0.40 & 0.30 & 0.35 \\\hline \end{array}$$
Which one of the following is a correct statement about arsenic concentration distribution?
- Arsenic concentration distribution is symmetric
- Arsenic concentration distribution is positively skewed
- Arsenic concentration distribution is negatively skewed
- Arsenic concentration is following Weibull distribution
