Use the given information to find the minimum sample size required to estimate a

Question

Use the given information to find the minimum sample size required to estimate an unknown population mean 22) How many women must be randomly selected to estimate the mean weight of women in one age 22) group. We want 90% confidence that the sample mean is within 34 lb of the population mean, and the population standard deviation is known to be 25 Ib A) 145 ) 147 C) 208 D) 148 23) How many students must be randomly selected to estimate the mean weekly earnings of students 23)B at one college? We want 95% confidence that the sample mean is within $2 of the population mean, and the population standard deviation is known to be $60. A) 4886 3458 C) 3047 D) 2435

Explanation / Answer

Solution:

22) Given = 3.4, = 25
- 1-0.90 = 0.10
Z/2 = Z0.10/2 = Z0.05 = 1.645

Sample size n = [Z/2 ()/ ]^2
= [1.645 (25)/3.4]^2
= 146.30 147
So, the right option is B) 147

23) Given = 2, = 60
- 1-0.95 = 0.05
Z/2 = Z0.05/2 = Z0.025 = 1.96

Sample size n = [Z/2 ()/ ]^2
= [1.96 (60)/2]^2
= 3457.44 3458
So, the right option is B) 3458

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

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