Step 1 :Given that the sample size (n) is 1594 and the number of successes (phones that broke before the warranty expires) is 82.
Step 2 :First, we calculate the sample proportion (p̂), which is the number of successes divided by the sample size. So, \(p̂ = \frac{x}{n} = \frac{82}{1594} = 0.0514\).
Step 3 :Next, we calculate the standard error of the proportion, which is the square root of \((p̂ * (1 - p̂)) / n\). So, the standard error is \(\sqrt{\frac{p̂ * (1 - p̂)}{n}} = \sqrt{\frac{0.0514 * (1 - 0.0514)}{1594}} = 0.0055\).
Step 4 :The confidence interval is then calculated as \(p̂ ± Z * \) standard error, where Z is the Z-score for the desired confidence level. For a 99% confidence level, the Z-score is approximately 2.576. So, the confidence interval is \(0.0514 ± 2.576 * 0.0055\).
Step 5 :Calculating the above expression, we get the confidence interval as \((0.0372, 0.0657)\).
Step 6 :\(\boxed{\text{Final Answer: With 99% confidence the proportion of all smart phones that break before the warranty expires is between 0.0372 and 0.0657.}}\)