Population and Sample Estimate

You ask 20 randomly chosen environmental scientists from your state to name their favorite way to eliminate waste. There are 400 environmental scientists in your state. Estimate the number of environmental scientists who prefer eliminating waste by recycling.

If 10,000 people vote in the upcoming mayoral election, estimate the number of voters who select Candidate B.

• 1,200

• 2,400

• 3,800

• 3,160

In order to use samples to estimate something from the population, the sample should be _________________ the population.

• exactly the same as

• nothing like

• representative of

• larger than

When one examines the entire population instead of a subgroup of the population, this is called a ____________.

• Sampling

• Census

• Bias

REFER TO THIS PROBLEM:   A cheese processing company wants to estimate the mean cholesterol content of all one-ounce servings of cheese. The estimate must be within 0.5 milligram of the population mean. Assume that the population standard deviation is 2.8 milligrams. What is the minimum required sample size to construct a 90% confidence interval for the population mean? What critical z-score value should be used?

• 1.645

• 1.96

• 2.575

• 2.8

A cheese processing company wants to estimate the mean cholesterol content of all one-ounce servings of cheese. The estimate must be within 0.5 milligram of the population mean. Assume that the population standard deviation is 2.8 milligrams. What is the minimum required sample size to construct a 90% confidence interval for the population mean? Round up your answer to the nearest whole number.

• 85

• 84

• 120

• 121

You will be conducting a study to estimate the average daily food expenditure of students. You want to be 95% confident that the sample mean will be within Php20 of the true mean. If you approximate the population standard deviation to be Php100 and assume an approximately normal distribution, what is the minimum sample size that you should get? Round up your answer to the nearest whole number.

• 96

• 97

• 67

• 68

You wish to estimate, with 99% confidence, the population proportion of employees who prefer a four-day work week. Your estimate must be accurate to within 4% of the population proportion. What is the minimum required sample size if no preliminary estimate is available? Round up your answer to the nearest whole number.

• 1,036

• 1,037

• 422

• 423

You wish to estimate, with 90% confidence, the population proportion of adults who read fiction books. Your estimate must be accurate to within 2% of the population proportion. A prior study found that 47% of adults read fiction books. What is the minimum required sample size? Round up your answer to the nearest whole number.

A cheese processing company wants to estimate the mean cholesterol content of all one-ounce servings of cheese. The estimate must be within 0.5 milligram of the population mean. What is the margin of error?