Margin of Error and Confidence Level

A recent survey found that 77% of high schoolers use their phones more than 4 hours a day on average. The margin of error was 3%. What is the interval for which we could expect to find the truth of the population?

• 77% - 80%

• 74% - 77%

• 74% - 80%

• 50 million high schoolers - 120 million

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

Why is a sample of 1000 people better than a sample of 100 people?

• It reduces the margin of error.

• Having more people creates more work.

• More people means that our results are always correct.

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CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A random sample of 100 WHS students found that 53 of them were in possession of a pencil. What is the sample proportion for this sample?

• 0.53
• 0.5
• 0.47
• 1

Tags

CCSS.HSS.IC.B.4

Determine whether the survey clearly projects a winner. According to the survey of students voting for student council president, 42% of the students said they will vote for Jada and 58% said they would vote for Sean. The survey's margin of error is 5%

• Jada wins

• Sean wins

• It's too close to tell

• It's a tie

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

CCSS.HSS.ID.B.5

A 95% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was ($139,048, $154,144). Give a practical interpretation of the interval.

• 95% of the sampled CEOs have salaries that fell in the interval $139,048 to $154,144

• We are 95% confident that the mean salary of all CEOs in the electronics industry falls in the interval $139,048 to $154,144.

• 95% of all CEOs in the electronics industry have salaries that fall between $139,048 to $154,144

• We are 95% confident that the mean salary of the sampled CEOs falls in the interval $139,048 to $154,144.

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A recent survey found that out of 400 random American adults, 89% pay their bills on time. The margin of error in this survey was 2%. What is the interval of values in which the truth is likely found?

• 89% - 91%

• 87% - 89%

• 87% - 91%

• 388 - 402

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A research team surveys 200 high schoolers at glenoak. They find that 57% of them drive to school every day. What is the margin of error? (Hint: Use the standard error formula)

• 95%

• 14%

• 7%

• 3%

Tags

CCSS.HSS.IC.B.4

What does SRS stand for?

• Simple Random Sample

• Survey Random Samples

• Simple Random Survey

• Sample Random Surveys

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.3

CCSS.HSS.IC.B.4

A study was commissioned to find the average water bill of a particular town.

The confidence interval created was between $44-$56.

What was the average of the sample? (Hint: What is the "center" of the interval above)

• $44

• $50

• $52

• $54

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

A study by the department of education in a certain state found that there was a mean SAT score of 534 with a margin of error of 20.

Create a confidence interval for the true mean.

• (534, 554)

• (514, 534)

• (514, 554)

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4