Estimate Unknown Population

What is a point estimate?

• average of sample values

• average of population values

• a single value that represents the unknown sample statistic

• a single value that represents the unknown population parameter

The scores of a random sample of 100 high school students on a standardized mathematics test in school A gave a mean of 78 and a standard deviation of 20. What is the best point estimate of the true average score in this standardized mathematics test?

• 20

• 78

• 95

• 100

The scores of a random sample of 100 high school students on a standardized mathematics test in school A gave a mean of 78 and a standard deviation of 20. Find the 95% confidence interval estimate for the true average score in mathematics in this standardized test.

• 1.96 to 3.92

• 76 to 80

• 74.08 to 81.92

• 74.80 to 81.29

If the mean of a sample is 203 and the margin of error is 4.6, what would be a reasonable mean for the population?

• 99.2

• 198.3

• 207.2

• 207.7

A sample of 600 ninth graders was selected at random and asked how much time they spend on homework each day. Of the ninth graders selected, 220 spend less than 2 hours on homework each day. If the conclusion was drawn that “approximately 1.35 million ninth graders spend less than 2 hours on homework each day,” which of the following is closest to the population, in millions, of ninth graders?

• 0.368

• 0.495

• 3.68

• 5.84

A sample of 600 ninth graders was selected at random and asked how much time they spend on homework each day. Of the ninth graders selected, 220 spend less than 2 hours on homework each day. If the conclusion was drawn that “approximately 1.35 million ninth graders spend less than 2 hours on homework each day,” which of the following is closest to the population, in millions, of ninth graders?

• 0.368

• 0.495

• 3.68

• 5.84

• between 5,700 and 6,000

• between 6,500 and 7,000

• between 5,400 and 6,600

• between 5,400 and 5,900

In a sample of 50 people in a town, the average yearly consumption of fruits is found to be 75 kilograms with a margin of error of 10 kilograms. Estimate the total yearly consumption of fruits in kilograms for the town's population of 2000 people.

• 130,000 kg-170,000 kg

• 110,000 kg-120,000 kg

• 180,000 kg- 200,000 kg

• 130 kg- 170 kg

A survey conducted on 100 households in a neighborhood finds that the average number of pets per household is 3 with a margin of error of ±0.5. Estimate the mean number of pets in all 500 households in the neighborhood.

• between 1250 pets-1750 pets

• between 125 pets- 175 pets

• between 1820 pets- 1940 pets

• between 182 pets- 194 pets

A survey of 200 students at a high school finds that the average amount of money spent on lunch per week is $25 with a margin of error of ±5. Estimate the total amount of money spent by all students at the high school on lunch per week if there are 1200 students.

• $15,000-$20,000

• $24,000-$36,000

• $770

• $40,000