Answer:
99% (two-sided) confidence interval for the true average echo duration is
0.87±0.10. (between 0.77 and 0.97 sec)
We are 99% confident that this interval contains the true population mean.
Explanation:
Confidence Interval can be calculated using M±ME where
- M is the sample average radar echo duration (0.87 sec)
- ME is the margin of error from the mean
And margin of error (ME) can be calculated using the formula
ME=
where
- z is the corresponding statistic for 99% confidence level (2.58)
- s is the standard deviation of the sample(0.40 sec)
- N is the sample size (101)
Then ME=
≈0.10
99% (two-sided) confidence interval for the true average echo duration is
0.87±0.10.