Complete the mcq:
Question 1
Sample with size n = 100 has mean = 30. Assuming the population standard deviation is 8, construct 95% confidence interval for population mean. Use formula on page 312, z?/2 = 1.96
between 28.4 and 31.6
between 27.0 and 33.0
between 26.1 and 34.2
between 24.1 and 35.9
Question 2
With sample mean x = 12.5, sample size n = 40 and population standard deviation = 4 find 99% confidence interval for population mean. Use formula on page 312 with z?/2 = 2.575
between 11.5 and 13.5
between 10.9 and 14.1
between 10.1 and 15.1
between 7.4 and 14.2
Question 3
Find t-value for sample size n = 16 and area to the right 0.10
2.015
1.860
1.725
1.341
Question 4
For sample mean x = 150, sample size n = 36 and sample standard deviation s = 40 find 80% confidence interval for population mean. Population standard deviation is not known, you should use formula on page 328 with t-value
135.6 to 148.4
154.2 to 175.8
141.3 to 158.7
162.3 to 187.5
Question 5
Use formula from material posted on Blackboard in for this week Lectures section to estimate population proportion. Sample proportion is ps = 0.48, sample size 125, zc = 1.96 (90% confidence level).
0.26 to 0.64
0.39 to 0.57
0.41 to 0.52
0.28 to 0.71