The life in hours of a 100-watt bulb is known to be approximately normally distr

Question

The life in hours of a 100-watt bulb is known to be approximately normally distributed. A random sample of 20 bulbs has a mean life of 2050 hours standard deviation of 12.5 hours. Construct a 95% two-sided confidence interval on the mean life. Also: Suppose we want the total width of the confidence interval on mean life to be five hours. What sample size should be used: if the desired confidence level is 95%? Note that the half-width of the confidence interval is equal to maximum error in estimation.

Explanation / Answer

Try this website: http://www.dimensionresearch.com/resources/calculators/sample_size.html.It helped me.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.