Measuring soluble sugar in plants, σ = 3
One plant is tested 16 times, giving mean of 137 mg/g of glucose
In this scenario, σ is known but the population mean, µ, is unknown. (Many chemical analyses often have known error distributions, though the population mean depends on the particular compound being analysed and must be estimated.)
Based on the known value of σ,
error ~ normal (0, σ = )
Drag the slider to see the error distribution for the data (n = 16).
Our estimate of 137 mg/g dry wt is unlikely to be more than 1.5 from the true glucose content for this plant .
Laboratory testing for soluble sugars in plants is not precise. One analysis gives glucose concentrations that are centred on the true concentration, µ mg/g dry weight.
X ~ normal (μ , σ = 3)