Q1 · medium · AI-verified
In stratified random sampling, a population of 1000 is divided into two strata of sizes 600 and 400. If a total sample of 100 is to be drawn using proportional allocation, how many units should be drawn from the stratum of size 400?
- 25
- 50
- 40
- 60
Q2 · medium · AI-verified
In a population of N = 1000 units, a simple random sample of n = 100 is selected. The sample proportion of defective items is p̂ = 0.15. What is the estimated standard error of the sample proportion (ignoring finite population correction)?
- 0.0357
- 0.1275
- 0.0150
- 0.0500
Q3 · medium · AI-verified
In stratified random sampling, if proportional allocation is used and the total sample size is n = 200, stratum 1 has N₁ = 300 units, stratum 2 has N₂ = 500 units, and stratum 3 has N₃ = 200 units, what is the sample size allocated to stratum 2?
- 80
- 50
- 150
- 100
Q4 · medium · AI-verified
A population has N = 500 units. A simple random sample of n = 50 units is drawn without replacement. If the sample mean is 40 and the population variance is 100, what is the standard error of the sample mean?
- 0.894
- 1.414
- 1.342
- 2.000
Q5 · medium · AI-verified
Which of the following sampling methods ensures that every member of the population has an equal and independent chance of being selected?
- Stratified Sampling
- Simple Random Sampling
- Cluster Sampling
- Systematic Sampling