A Cell Phone Service Provider Has Selected a Random Sample

question 47

Multiple Choice

A cell phone service provider has selected a random sample of 20 of its customers in an effort to estimate the mean number of minutes used per day. The results of the sample included a sample mean of 34.5 minutes and a sample standard deviation equal to 11.5 minutes. Based on this information, and using a 95 percent confidence level:

• A) the critical value is z = 1.96
• B) the critical value is z = 1.645
• C) the critical value is t = 2.093
• D) The critical value can't be determined without knowing the margin of error.

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Definitions:

Imitate

The action of copying or mimicking the behaviors, actions, or appearances of someone else.

Parents Do

The actions, behaviors, and decisions made by parents in raising their children, including nurturing, disciplining, and supporting their development.

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The experience of being a direct observer to the act of murder, which can have profound psychological effects on individuals.

Elementary School Years

The period in a child's education that typically covers grades 1 through 5 or 6, focusing on foundational academic skills.