Estimate from Sample Data

Farmer Joe separates his apple tree farm into 10 regions.  He counts the number of apples produced in just one of the regions and uses that estimate to predict the number of apples produced on the whole farm.  This is _______ sampling.

• Simple

• Cluster

• Stratified

• Systematic

Sra. Garces wants to find the average height of all her students in her classes. She decides to use the first 5 people who walk in the door. Is this a good representative sample?

• Yes

• No

TRUE or FALSE: If we assume that a set of PERFORMANCES is a random sample from the population of all possible PERFORMANCES an athlete could have had, we can use a confidence interval to estimate the ABILITY of an athlete.

• TRUE

• FALSE

Which of the following is an example of an interval estimate?

• point estimate 

• critical value

• confidence interval

• statistic

A random sample of 60 was taken from a shipment of 12,500 light bulbs. There were 2 defective bulbs in the sample.

How many defective bulbs would you expect in the entire shipment?

• 250 bulbs

• 417 bulbs

• 2,500 bulbs

• 4,167 bulbs

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

The normal curve shown represents the sampling distribution of a sample mean for sample size n = 25, selected at random from a population with standard deviation sd. Which of the following is the best estimate of the standard deviation of the population, sd ?75

• 3

• 6

• 15

• 30

• 75

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 company polls a group of 1,067 people randomly selected to represent New York City. The company determines that 10% of the sample group does not like cheese, while the remaining 90% does like cheese. The poll is true with a 3% margin of error. If there are 8.5 million people in New York City, what is the best estimate for the number of people who do not like cheese?

• 850,000 people

• Between 425,000 and 1,275,000 people

• Between 595,000 and 1,105,000 people

• Between 722,500 and 977,500 people

Complete the equation: 
point estimate +/- _____

• standard deviation

• margin of error

• critical value

• confidence level