Determining Sample Size

If the margin of error decreases, what happens to the required sample size?

• Remains the same

• Increases

• Decreases

• Fluctuates

Tags

CCSS.HSS.IC.B.4

If the confidence level is increased, what happens to the margin of error?

• Decreases

• Increases

• Remains the same

• Fluctuates

Tags

CCSS.HSS.IC.B.4

A political pollster wants to estimate the proportion of voters who support a particular candidate with a margin of error of 3% and a 99% confidence level. If the estimated proportion of voters supporting the candidate is 0.6, what is the minimum sample size required?

• 1766

• 1767

• 1769

• 1770

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A quality control manager wants to estimate the proportion of defective items produced by a machine with a margin of error of 0.02 and a 95% confidence level. If historical data suggest that the proportion of defective items is around 0.1, how many items should be sampled?

• 864

• 865

• 608

• 609

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

CCSS.HSS.ID.A.4

A researcher wants to estimate the average height of students in a university with a margin of error of 0.05 meters and a 90% confidence level. If the population standard deviation is known to be 0.2 meters, what sample size is required?

• 26

• 27

• 44

• 43

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

An economist wants to estimate the average monthly income of households in a city with a margin of error of $100 and a 95% confidence level. If the population standard deviation is estimated to be $500, how many households should be sampled?

• 67

• 68

• 97

• 98

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A researcher wants to estimate the average weight of apples in a population with a margin of error of 0.2 pounds and a 95% confidence level. If the population standard deviation is known to be 0.75 pounds, what sample size is required?

• 32

• 33

• 55

• 54

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A manufacturing company wants to estimate the mean time taken to assemble a product with a margin of error of 2 minutes and a 90% confidence level. If the standard deviation of assembly time is 10 minutes, how many units should be sampled?

• 68

• 67

• 42

• 41

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

A market researcher wants to estimate the proportion of smartphone users who prefer a specific brand with a margin of error of 3% and a 95% confidence level. If the estimated proportion is 0.6, what sample size is required?

• 121

• 1024

• 1025

• 122

Tags

CCSS.HSS.IC.B.4

A wildlife biologist wants to estimate the proportion of a rare species in a forest with a margin of error of 0.02 and a 90% confidence level. If historical data suggest that the proportion of the species in the forest is around 0.05, how many sampling sites should be selected?

• 17

• 16

• 196

• 195

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4