Answer:
95% (two-sided) confidence interval for the proportion of all dies that pass the probe is between 0.470 and 0.574
Step-by-step explanation:
Confidence interval can be calculated as p±ME where
- p is the sample proportion of dies that pass the probe
- ME is the margin of error
and margin of error (ME) around the mean can be found using the formula
ME= where
- z is the corresponding statistic in 95% confidence level (1.96)
- p is the sample proportion (
)
- N is the sample size (356)
Using the numbers in the formula we get
ME= ≈0.052
then the 95% confidence interval would be 0.522±0.052