15-17. According to a study published in the Journal of Economic Perspectives (2

Question

15-17. According to a study published in the Journal of Economic Perspectives (2014), roughly 12 percent of humans are left-handed. Let p denote the proportion of left-handed childern in a random sample of 144 school children. 15. The standard deviation of p is closest to: (a) .001 (b).022 (c).027 (d) .049 (e).059 16. The probability that the sample proportion is at most 0.14 is closest to: (a) .12 (b) .46 (c) .88 (d) 54 (e) .77 17. The probability that the sample proportion is within plus/minus 0.02 of the population proportion of 0.12 is closest to: (a).12 (b) .46 (c).88 (d) .54 (e) .7 18. A study is being planned to estimate the incidence of sexual assault at a university with a margin of error of 0.04 and at a confidence level of 0.96. Assume that the incidence of sexual assault is at most 0.30. What is minimum sample size necessary to achieve this goal? (a) 106 (b) 213 (c) 420 (d) 554 (e) 859

Explanation / Answer

here p=0.12

and n=144

15) std error =(p(1-p)/n)1/2 =0.027

option C

16)

P(X<0.14)=P(Z<(0.14-0.12)/0.027)=P(Z<0.7385)=0.77

option E

17)

P(-0.02/0.027<Z<0.02/0.027)=P(-0.7385<Z<0.7385)=0.77-0.23 =0.54

option d

18)

here margin of error E =0.04

p =0.3

and for 96% CI ;z=2.0537

hence required sample size n=p(1-p)*(z/E)2 =~ 554

option D

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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