This Question: 1 pt 8 of 21 (4 complete) This Test: 21 pts possibl A study of 42

Question

This Question: 1 pt 8 of 21 (4 complete) This Test: 21 pts possibl A study of 420,049 cell phone users found that 136 of them developed cancer of the brain or nervous system. Prior to this study of cell phone use. cancer was found to be 0.0334% for those not using cell phones. Complete parts (a) and (b). a. Use the sample data to construct a 90% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system. Round to three decimal places as needed.) b. Do cell phone users appear to have a rate of cancer of the brain or nervous system that is different from Why or why not? the rate of such cancer among those not using cell phones A. No, because 00334% is not included in the confidence interval B. Yes, because 0 0334% is included in the confidence interval. c. Yes, because 0.0334% is not included in the confidence interval. No, because 00334% is included in the confidence interval. 0 D.

Explanation / Answer

For a 90% confidence interval, we look for z = 0.05, the z-score with 5% of the area to its right. From the z-score table, we see that that z-score is 1.645 .

Now, n= 420,049 ; p = 0.000334 ; q = 1- p = 0.999666

? = ? pqn = ? (0.000334 x 0.999666 x 420,049 ) = 11.8427

Therefore, the confidence interval is (136 ± 1.645 x 11.8427) / n = (0.0003702, 0.0002774)

Converting these proportions to percentages we get:

(a) 0.02774% < p < 0.03702%

(b) Option D : No, because 0.0334% is included in the confidence interval.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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