Determining a Sample Size for a Confidence Interval for a Population Proportion Based on Confidence & Margin of Error

  • 1.

    Oliver wants to know how many children in a city prefer coffee over tea. Determine the number of children that should be sampled in order to create a 70% confidence interval with a margin of error that is no more than 10%.

    Answers:

    • 22

    • 28

    • 25

    • 31

  • 2.

    What sample size would be needed to create an 85% confidence interval with a margin of error that is less than or equal to 5%?

    Answers:

    • 213

    • 218

    • 208

    • 203

  • 3.

    Jeanne is surveying women in a certain population to determine how many of them get a proper sleep of more than 7 hours each night. Which of the following options indicates the number of women that should be sampled to create a 95% confidence interval with a margin of error no larger than 7%?

    Answers:

    • 166

    • 176

    • 186

    • 196

  • 4.

    Choose the sample size that would be needed in order to create a 99% confidence interval with a margin of error that is no more than 6%.

    Answers:

    • 483

    • 473

    • 463

    • 453

  • 5.

    Mr. Brown is interested in knowing the proportion of students in his class that like mathematics. Find the number of students that should be sampled to construct a 90% confidence interval with a margin of error that is less than or equal to 5%.

    Answers:

    • 373

    • 271

    • 173

    • 473

  • 6.

    Determine the sample size needed for creating a 95% confidence interval with a margin of error that is equal to or smaller than 8%.

    Answers:

    • 156

    • 146

    • 151

    • 141

  • 7.

    Noah wants to know the proportion of men in a certain area that like chocolate cake. Identify the number of men that should be sampled to create a 95% confidence interval with a margin of error that is no larger than 15%.

    Answers:

    • 48

    • 43

    • 53

    • 58

  • 8.

    What should the sample size be in order to create a 98% confidence interval with a margin of error that is less than or equal to 12%?

    Answers:

    • 75

    • 65

    • 85

    • 95

  • 9.

    Angelo wants to know the proportion of individuals in an area that enjoy participating in sports of any kind. Which of the following choices indicates the number of individuals that should be sampled to construct an 80% confidence interval with a margin of error that is no more than 25%?

    Answers:

    • 17

    • 9

    • 7

    • 19

  • 10.

    Select the accurate sample size for creating a 75% confidence interval with a margin of error that is no larger than 21%.

    Answers:

    • 5

    • 15

    • 18

    • 8

  • 11.

    Dr. Shally is interested in knowing what proportion of girls in her state eat a healthy and balanced diet. Find the number of girls to be sampled in order to construct a 95% confidence interval with a margin of error that is less than or equal to 12%.

    Answers:

    • 51

    • 57

    • 67

    • 61

  • 12.

    Determine the sample size that would be needed to construct a 90% confidence interval with a margin of error that is no more than 6%.

    Answers:

    • 180

    • 188

    • 210

    • 200

  • 13.

    Jannie is a farmer. She wants to know how many plants on her farm are thriving. Determine the number of plants to be sampled in order to create an 80% confidence interval with a margin of error that is no larger than 13%.

    Answers:

    • 50

    • 25

    • 100

    • 75

  • 14.

    What sample size would be needed to create a 98% confidence interval with a margin error that is equal to or smaller than 10%?

    Answers:

    • 126

    • 121

    • 136

    • 131

  • 15.

    Daniel would like to know the proportion of red cars in a particular city. Which of the given options is the number of cars that should be sampled to create an 85% confidence interval with a margin of error that is less than or equal to 14%?

    Answers:

    • 21

    • 31

    • 27

    • 37

  • 16.

    Choose the accurate sample size for creating a 95% confidence interval with a margin of error that is equal to or smaller than 6%.

    Answers:

    • 277

    • 287

    • 257

    • 267

  • 17.

    Sarah works in a factory that manufactures bulbs. She wants to know the proportion of defective bulbs. Find the number of bulbs to be sampled for constructing a 70% confidence interval with a margin of error no more than 15%.

    Answers:

    • 23

    • 17

    • 13

    • 27

  • 18.

    Identify the sample size needed for having a 98% confidence interval with a margin of error that is no larger than 8%.

    Answers:

    • 203

    • 223

    • 213

    • 233

  • 19.

    The head of a company wants to know what proportion of female workers at the company are married. Identify the number of female workers to be sampled to create an 80% confidence interval with a margin of error that is less than or equal to 20%.

    Answers:

    • 13

    • 17

    • 15

    • 11

  • 20.

    What should be the sample size be in order to to create an 85% confidence interval with a margin of error that is no larger than 6%?

    Answers:

    • 133

    • 166

    • 155

    • 144

  • 21.

    A person is interested in knowing the proportion of adults in a specific community who have a permanent job. Which of the given choices is the number of adults that should be sampled to create a 95% confidence interval with a margin of error that is no more than 5%?

    Answers:

    • 375

    • 385

    • 365

    • 395

  • 22.

    Select the accurate sample size for creating a 90% confidence interval with a margin of error that is equal to or smaller than 7%.

    Answers:

    • 137

    • 135

    • 133

    • 139

  • 23.

    William's father works for a company that makes and sells real floral garlands. William wants to know the proportion of garlands made with roses. Find the number of garlands to be sampled for constructing a 75% confidence interval with a margin of error that is less than or equal to 10%.

    Answers:

    • 48

    • 34

    • 38

    • 44

  • 24.

    Calculate the sample size needed to construct a 98% confidence interval with a margin of error that is no more than 7%.

    Answers:

    • 266

    • 288

    • 255

    • 277

  • 25.

    Dr. Smith wants to examine elephants in a country to determine what proportion of them are completely healthy. Determine the number of elephants that should be sampled to create a 95% confidence interval with a margin of error that is no larger than 10%.

    Answers:

    • 91

    • 101

    • 97

    • 107

  • 26.

    What should the sample size be to create a 99% confidence interval with a margin of error that is no larger than 8%?

    Answers:

    • 251

    • 260

    • 256

    • 266

  • 27.

    Jonathan is interested in knowing the proportion of men that are literate at a certain institution. Which of the given options is the number of men that should be sampled for creating a 95% confidence interval with a margin of error that is smaller than or equal to 4%?

    Answers:

    • 801

    • 501

    • 701

    • 601

  • 28.

    Choose the accurate sample size for creating a 90% confidence interval with a margin of error that is less than or equal to 8%.

    Answers:

    • 97

    • 91

    • 106

    • 101

  • 29.

    A person is interested in knowing what proportion of a certain population of children play outdoor games. Find the number of children the person must sample for constructing an 80% confidence interval with a margin of error that is no more than 12%.

    Answers:

    • 25

    • 29

    • 35

    • 39

  • 30.

    Determine the sample size needed in order to create a 90% confidence interval with a margin of error that is equal to or smaller than 4%.

    Answers:

    • 421

    • 411

    • 423

    • 416

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