Perform a Runs Test for Randomness $$\alpha$$ = 005

question 25

Essay

Perform a runs test for randomness. Be sure to do the following: Identify the claim mathematically and state the null
and alternative hypotheses. Determine the critical value and find the test statistic. Decide whether to reject or fail to
reject the null hypothesis and interpret the decision in the context of the original claim.
-A telemarketer solicited households to change their long-distance carrier. The results for one afternoon are
shown, where C represents the households that changed their carrier and S represents the households that kept
their existing carrier. Can you conclude that the sequence of results is random? Use $$\alpha$$ = 0.05. $$\begin{array} { l l l l l l l l l l l } \mathrm { C } & \mathrm { C } & \mathrm { C } & \mathrm { S } & \mathrm { C } & \mathrm { S } & \mathrm { C } & \mathrm { S } & \mathrm { S } & \mathrm { C } & \mathrm { C } \\\mathrm { S } & \mathrm { C } & \mathrm { S } & \mathrm { C } & \mathrm { S } & \mathrm { C } & \mathrm { S } & \mathrm { S } & \mathrm { C } & \mathrm { S } & \mathrm { C }\end{array}$$

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Definitions:

External Validity

The extent to which the results of a study can be generalized to other situations, populations, or time periods beyond the study itself.

Diffusion

In experimental design, the problem of a treatment effect spreading from group to group as people communicate.

Treatment Effect

The difference in outcomes between a group receiving an intervention and a control group in an experimental study.

Factorial Designs

Experimental designs that manipulate two or more variables at a time.