- Hypothesis Testing
- Frequentist Inference
- Confidence Interval
Confidence interval for mean.
The life in hours of a 75 watt light bulb is known to be normally distributed with std deviation of 25 hours. A random sample of 20 bulbs has a mean life of 1014 hours.
a) Construct a 95% two sided confidence interval on the mean life.
b) Construct a 95% lower-confidence bound on the mean life.
Compare the lower bound of this confidence interval with the one from part a
Step by step method for computing confidence interval for mean is given in the answer.