The probability that a person has an unlisted phone number is0.15. The district

Question

The probability that a person has an unlisted phone number is0.15. The district manager of a political action group isphoning people urging them to vote. In a district with 416households all households have phones. What is the probabilitythat: 1.) 50 or fewer households in the district will have unlistednumbers? 2.)345 or more will have listed phone numbers? 3.) between 40 and 80 will have unlisted phone numbers? The probability that a person has an unlisted phone number is0.15. The district manager of a political action group isphoning people urging them to vote. In a district with 416households all households have phones. What is the probabilitythat: 1.) 50 or fewer households in the district will have unlistednumbers? 2.)345 or more will have listed phone numbers? 3.) between 40 and 80 will have unlisted phone numbers?

Explanation / Answer

E= NP=4 16 x .15 = 62.4

Var = np (1-p) = 53

SD=sqrt Var = 7.3

50 is 62.4-50 / 7.3 = 1.69 Z score or 4.5%

That is how you solve this type of problem

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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