The proportion of defective parts produced by ABC Company was equal to0.20when the owner ordered some changes in the assembly process. After the changes were put into effect, a random sample of40parts was tested, revealing a total of6defective parts.

Do the sample data provide sufficient sample evidence to conclude that the proportion of defective parts produced by ABC Companybecame different from 0.20after the changes in assembly process?

Test the appropriate hypothesis usingcritical value approach. Use level of significance =0.05. a. State null and research hypotheses:

₀H:___________________

₁H:___________________

b. Find the observed value of test statistic. The observed value of test statistic is_obs.z=__________________________ (Keep 2 digits after decimal point in the expression for observed value of test statistics)

c. State the rejection region.

The rejection region is ___________________________________________

d. Insert the wordsufficientorinsufficientinto the following statement.

There is _______________________ sample evidence that the proportion of defective parts has been changed after the changes in the assembly process were put into effect.

Please help with this Practice Question.