A manufacturing company produces electric insulators. You define the variable of

Question

A manufacturing company produces electric insulators. You define the variable of interest as the strength of the insulators. If the insulators break when in use, a short circuit is likely. To test the strength of the insulators, you carry out destructive testing to determine how much force is required to break the insulators. You measure force by observing how many pounds are applied to the insulator before it breaks. The data shown below represent the amount of force required to break a sample of 30 insulators. Complete parts a through c below 4 28 10 4 17 42 17 29 20 20 29 23 23 32 24 21 37 24 27 D 57 32 16 27 24 42 a. Construct a 95% confidence interval for the population mean force Di L (Round to two decimal places as needed )

Explanation / Answer

a. Solution :

Given that 4,4,4,4,11,17,20,23,21,27,16,28,22,17,27,29,29,32,37,57,2,10,42,42,24,20,23,24,24,32

=> Mean x = 22.4

=> Mean = sum of terms/number of terms

= 672/30

= 22.4

=> standard deviation = 12.73

=> For 95% confidence interval , Z = 1.96

=> The 95% confidence interval for the population mean is

=> x +/- Z*/sqrt(n)

=> 22.4 +/- 1.96*12.73/sqrt(30)

=> 17.84 <= <= 26.96

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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