Question

lab scale known to have a standard deviation of 0.001gram, speimen weghtted 8 times. average weiht is 4.1602 gram. what is 99% confidence interval

Answer 1

Answer:

$99\% CI=4.1602 \pm 0.0009$

Step-by-step explanation:

From the question we are told that:

Sample size $n=8$

Mean $\=x=4.1602$

Standard deviation $\sigma=0.001gram$

Generally 99\% confidence from table  is mathematically given by

 $99\% CI=4.1602 \pm *2.576*\frac{0.001}{\sqrt{{8}}}$

 $P(-z<x<z)=0.99$

 $Z_{\alpha/2}=2.576$

Generally the equation for 99\% confidence level (CI)  is mathematically given by

 $99\% CI=\=x \pm Z_{\alpha/2*\frac{\sigma}{\sqrt{{n}}}$

 $99\% CI=4.1602 \pm 0.0009$