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

`99\% CI=4.1602 \pm 0.0009`

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`