Attached below are screenshots from the article Go to the attached link. Read th

Question

Attached below are screenshots from the article

Go to the attached link. Read the article carefully and pay particular attention to the note on methodology at the end. 1, Create a 95% confidence interval for the percent of adults in the US who support strengthening law and order 2. Create a 95% confidence interval for the percent of adults in the US who support reducing the bias against minorities in law enforcement. 3. If a newspaper story reported that the percent in favor of strengthening law and order was in a statistical dead-heat (a tie) with the percent of those favoring reducing bias against minority what would that mean. Your answer must include reference to comparing the two confidence intervals and a discussion of what margin of error means.

Explanation / Answer

Question 1

First of all we have to find the 95% confidence interval for the proportion of adults in US who support strengthening law and order.

We are given

P = 0.49

n = 1017

Confidence level = 95%

Critical value Z = 1.96

(By using z-table)

Confidence interval = P -/+ Z*sqrt(P*(1 – P)/n)

Confidence interval = 0.49 -/+ 1.96*sqrt(0.49*(1 – 0.49)/1017)

Confidence interval = 0.49 -/+ 1.96* 0.0157

Confidence interval = 0.49 -/+ 0.0307

Lower limit = 0.49 - 0.0307 = 0.4593

Upper limit = 0.49 + 0.0307 =0.5207

Question 2

Here, we have to find 95% confidence interval for the percent of adults in US who support reducing the bias against minorities in law enforcement.

We are given

P = 0.43

n = 1017

Confidence level = 95%

Critical value Z = 1.96

(By using z-table)

Confidence interval = P -/+ Z*sqrt(P*(1 – P)/n)

Confidence interval = 0.43 -/+ 1.96*sqrt(0.43*(1 – 0.43)/1017)

Confidence interval = 0.43 -/+ 1.96* 0.0156

Confidence interval = 0.43 -/+ 0.0305

Lower limit = 0.43 - 0.0305 = 0.4095

Upper limit = 0.43 + 0.0305 =0.4705

Part C

From above two confidence intervals for population proportions, it is observed that there is some common (tie up) area between these two confidence intervals. Although this area is common, it does not indicate that some population is in favour of both. This is due to margin of error for the given two confidence intervals. Margin of error is the specific up and down range from sample proportion for the estimate of population proportion.

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