Final answer:
To find the estimated success rate of challenges with a 95% confidence interval, divide the number of successful challenges by the total challenges and calculate the margin of error using the standard error. The correct option is Option 2: 23.31% (21.98%, 24.64%).
Step-by-step explanation:
To find the estimated success rate of challenges with a 95% confidence interval, we can use the formula for estimating a proportion:
Success rate = (Number of successful challenges / Total challenges) * 100%
Using the given information, the success rate is (31 / 133) * 100% = 23.31%.
To calculate the 95% confidence interval, we can use the formula:
Lower bound = Success rate - Margin of error
Upper bound = Success rate + Margin of error
The margin of error is calculated as:
Margin of error = Critical value * Standard error
Using a 95% confidence level, the critical value is 1.96 (for a sample size greater than 30).
Using the formula for the standard error:
Standard error = √(Success rate * (1 - Success rate) / Total challenges)
Plugging in the values, the standard error is √((0.2331 * 0.7669) / 133). This results in a standard error of approximately 0.025.
So, the 95% confidence interval is 23.31% ± (1.96 * 0.025), which gives us the range of (21.98%, 24.64%). Therefore, the correct option is Option 2: 23.31% (21.98%, 24.64%).