Question

Stephen has found that the average weight packed gummy candies selected from a normally distributed population is 200g with standard deviation of 8g. Find the point and interval estimates of all gummy candies using 99% confidence level.

Answer 1

$\bar{x}=200g, \sigma=8g\\ \alpha=0.01,\\ z_{\frac{\alpha}{2}}=z_{0.025}=1.96$

Confidence interval$= \bar{x}\pm z_{0.025}\times \sigma$

$=200\pm 1.96\times 8\\=(200\pm 15.68)\\=(184.32,215.68)$