The working curve for the determination of dopamine at a nano needle electrode by differential-pulse voltammetry (Figure 25-38) was constructed from the following table of data.
![695_a070c01f-0531-4870-a06c-d6291c3da19d.png](https://secure.tutorsglobe.com/CMSImages/695_a070c01f-0531-4870-a06c-d6291c3da19d.png)
(a) Use Excel to perform a least-squares analysis of the data to determine the slope, intercept, and regression statistics, including the standard deviation about regression.
(b) Use your results to find the concentration of dopamine in a sample solution that produced a peak current of 3.62 nA. This value is the average of duplicate experiments.
(c) Calculate the standard deviation of the unknown concentration and its 95% confidence interval assuming that each of the data in the table was obtained in a single experiment.
![2473_ab79f6c5-d413-4014-9379-03ae72e157a3.png](https://secure.tutorsglobe.com/CMSImages/2473_ab79f6c5-d413-4014-9379-03ae72e157a3.png)