Question

can you show your work please

Homework: Sec 9.4 Score: 0 of 1 pt 9.4.81-P HW Score: 0%, 0 of 6 n Help The test statistic is z Round to two decimal places as needed.) ents Clear All DOLL

Answer 1

9.4.81-P)

Level of significance = 0.05

Here population standard deviation is known so we have to use z-test statistic.

Test statistic is

$z =\frac{\bar{x}-\mu }{\sigma /\sqrt{n}}$

$z =\frac{19-22 }{8 /\sqrt{20}}=\frac{-3}{1.7889}=-1.68$

Critical value = 1.96 ( Using z table)

Critical value > Test statistic | z | we fail to reject the null hypothesis.

Conclusion:

The population mean is 22