Chapter A1, Problem A1.14QAP

Interpretation Introduction

(a)

Interpretation:

The standard deviation for the chlorinated hydrocarbons in the air sample is 0.030ppm by using established method. The 95% confidence interval for the mean of the four measurement obtained by this method is to be determined.

Concept introduction:

The 95% confidence interval for each data is calculated as-

$CI,\mu =\overline{x}\pm \frac{ts}{\sqrt{N}}$

Where,

N = degree of freedom

$\mu$ = confidence interval

$\overline{x}$ = mean

s = standard deviation

t = constant

Interpretation Introduction

(b)

Interpretation:

The standard deviation for the chlorinated hydrocarbons in the air sample is 0.030ppm by using established method. The number of measurements is to be determined when 95% confidence interval is to be $\pm 0.017$.

Concept introduction:

The 95% confidence interval for each data is calculated as-

$CI,\mu =\overline{x}\pm \frac{ts}{\sqrt{N}}$

Where,

N = degree of freedom

$\mu$ = confidence interval

$\overline{x}$ = mean

s = standard deviation

t = constant