Question

which substance has the smallest standard deviation?
uric acid
phosphate
oxalate

Explanation:

Step1: Understand standard deviation

Standard deviation measures data spread. Smaller spread means smaller standard deviation.

Step2: Analyze error bars

In the bar - chart, error bars represent variability. The shorter the error bar, the smaller the spread.

Step3: Compare error bars

Looking at the chart, the error bar for phosphate is the shortest.

Answer:

phosphate