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I have 4 problems if the tutor is willing to help, I failed my test and am looking to understand these in hopes of a chance to retake the test

I have 4 problems if the tutor is willing to help, I failed my test and am looking-example-1
User Qwe
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1 Answer

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23 votes

Answer

Question 3

Option A is correct.

Margin of Error = 0.071

Question 4

Option A is correct.

95% Confidence interval = 0.062 < p < 0.121

Step-by-step explanation

Question 3

Confidence Interval for the population proportion is basically an interval of range of values where the true population proportion can be found with a certain level of confidence.

Mathematically,

Confidence Interval = (Sample proportion) ± (Margin of error)

Margin of Error is the width of the confidence interval about the mean.

Now, here, we are given the confidence interval and asked to find the margin of error.

Sample Proportion = Population proportion = p

Let Margin of Error be E

Lower limit of confidence interval = p - E = 0.179

Upper limit of confidence interval p + E = 0.321

Now, we have a simultaneous equation

p - E = 0.179

p + E = 0.321

Add the two equations

2p = 0.179 + 0.321

2p = 0.5

Divide both sides by 2

p = 0.25

We can then solve for E

p - E = 0.179

0.25 - E = 0.179

E = 0.25 - 0.179

E = 0.071

Question 4

Confidence Interval for the population proportion is basically an interval of range of values where the true population proportion can be found with a certain level of confidence.

Mathematically,

Confidence Interval = (Sample proportion) ± (Margin of error)

Sample proportion = p = (33/362) = 0.0912

Margin of Error is the width of the confidence interval about the mean.

It is given mathematically as,

Margin of Error = (Critical value) × (standard Error)

Critical value at 95% confidence interval for sample size of 362 is obtained from the z-tables.

Critical value = 1.960

Standard error or deviation of the sample proportion = σₓ = √[p(p – 1)/n]

p = 0.0912

1 - p = 0.9088

n = sample size = 362

σₓ = √[(0.0912 × 0.9088)/362] = 0.0151

95% Confidence Interval = (Sample proportion) ± [(Critical value) × (standard Error)]

CI = 0.0912 ± (1.96 × 0.0151)

CI = 0.0912 ± 0.0297

95% CI = (0.062, 0.121)

95% Confidence interval = 0.062 < p < 0.121

Hope this Helps!!!

User Vincent L
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