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a bottle maker believes that 33% of his bottles are defective. if the bottle maker is right, what is the probability that the proportion of defective bottles in a sample of 730 bottles would differ from the population proportion by less than 3% ? round your answer to four decimal places.

User Zmilojko
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1 Answer

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Final answer:

The probability that the proportion of defective bottles in a sample of 730 bottles would differ from the population proportion by less than 3% is approximately 0.0697.

Step-by-step explanation:

To calculate the probability that the proportion of defective bottles in a sample of 730 bottles would differ from the population proportion by less than 3%, we can use the normal approximation to the binomial distribution.

Calculate the Standard Deviation

First, we need to calculate the standard deviation (σ) using the formula:

σ = √(p*(1-p)/n)

Where:

p = population proportion of defective bottles (0.33)

n = sample size (730)

σ = √(0.33(1-0.33)/730)

= √(0.330.67/730)

= √(0.2211/730)

= 0.01742

Calculate the Margin of Error

The margin of error is given by multiplying the standard deviation by the z-score corresponding to the desired level of confidence.

Since we want to find the probability that the proportion differs by less than 3%, we can use a z-score that corresponds to a 97% confidence level, which is approximately 2 standard deviations from the mean.

Margin of Error = z * σ

= 2 * 0.01742

=0.03484

Calculate Lower and Upper Bound for Proportion

Next, we calculate the lower and upper bounds for the proportion of defective bottles in the sample:

Lower Bound = p - Margin of Error

= 0.33 - 0.03484

= 0.29516

Upper Bound = p + Margin of Error

= 0.33 + 0.03484

≈ 0.36484

Calculate Probability

Finally, we can calculate the probability that the proportion of defective bottles in a sample of 730 bottles would differ from the population proportion by less than 3% using these bounds.

Probability = Upper Bound - Lower Bound

≈ 0.36484 - 0.29516

≈ 0.0697

Therefore, the probability that the proportion of defective bottles in a sample of 730 bottles would differ from the population proportion by less than 3% is approximately 0.0697.

User Moby J
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