A Consumer Protection Agency Is Comparing the Work of Two $n _ { 1 } = n _ { 2 } = 195$

question 29

Multiple Choice

A consumer protection agency is comparing the work of two electrical contractors. The agency plans to inspect residences in which each of these contractors has done the wiring in order toestimate the difference in the proportions of residences that are electrically deficient. Suppose the proportions of residences with deficient work are expected to be about .1 for both contractors. How many homes should be sampled in order to estimate the difference in proportions using a 90% confidence interval of width .1?

• A) \(n _ { 1 } = n _ { 2 } = 195\)
• B) \(n _ { 1 } = n _ { 2 } = 98\)
• C) \(n _ { 1 } = n _ { 2 } = 217\)
• D) \(n _ { 1 } = \mathrm { n } _ { 2 } = 390\)

---

Definitions:

Central Canal

is the cerebrospinal fluid-filled space that runs longitudinally through the length of the entire spinal cord.

Third Ventricle

A narrow, fluid-filled space in the brain located between the two halves of the thalamus, part of the ventricular system that circulates cerebrospinal fluid.

Cerebral Aqueduct

A narrow channel located within the brain that connects the third ventricle to the fourth ventricle, allowing cerebrospinal fluid to flow between these areas.

Spinal Canal

A narrow space within the spine running through the center of the spinal column, providing protection and support to the spinal cord.