Question

A random sample of size 100 has a standard deviation of 5.Find

maximum error with 95% confidence.

Answer 1

The critical value for $\alpha = 0.05$ is $z_c = z_{1-\alpha/2} = 1.96.$

Maximum error

$$E=z_c\times\dfrac{\sigma}{\sqrt{n}}$$

$$E=1.96\times\dfrac{5}{\sqrt{100}}=0.98$$