To constructed a CI of level 100(1 - alpha)% for the true average of the percent

Question

To constructed a CI of level 100(1 - alpha)% for the true average of the percentage content of lead oxide (PbO) in the crystals produced by a manufacturer, we randomly selected 33 of their products and measured the percentage of PbO in each of them. After presenting the result to the managers, they said that they would like to have a CI with the same level, of 100(1 - alpha)%, whose length is 2 times shorter that the one that we presented. To meet this demand how many crystal items we need to use? Justify your answer.

Explanation / Answer

Answer:

We need to use 4*33=132 crystal items.

Margin of error ME = z*sd/sqrt(n) = z*sd/sqrt(33)

Length is shorter by two times .

Therefore ME/2 = z*sd/2*sqrt(33)

The required sample size is 22*33=132

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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