Inferences and Statistics

The results of a random survey showed that 42 out of 84 people plan to vote for Coach Vasquez for teacher of the month. Which is the best prediction of the total number of votes he will receive if 2,000 people vote?

• 825

• 750

• 1200

• 1000

14 out of 30 people like the beach. How many out of 9000 people should like the beach?

• 4,200

• 420

• 42

• 42,000

Herald is keeping track of eagles. To do so, he put tags on 25 eagles and released them. Later, he catches 120 eagles; 16 eagles were tagged. Find the best estimate for the Eagle population?

• 205

• 310

• 400

• 188

A manager samples receipts of every fifth person in line. Out of 50 people, 4 had a mispriced item. If 600 people go to the store each day, how many can you expect to have a mispriced item?

• 50 people

• 80 people

• 48 people

• 12 people

A representative sample of 80 customers in a clothing store was surveyed about how they paid for their purchases. The table shows the responses. Based on the results, which of the following are valid inferences. Select two answer choices.

• Tomorrow, 8 out of the first 80 customers will for sure pay with a gift card.

• In a group of 40 customers, it is expected that about 10 will pay with cash.

• About 30% of all the store's customers will pay with a credit card.

• A sample of 100 customers would provide less reliable data.

The manager of a music store surveyed a random sample of customer who shop in the store about their favorite type of music. The table shows the number of customers who selected each type of music. Based on the information in the table, which inference about the favorite type of music of all the customers who shop in the music store appears to be valid?

• They are certain to select rock or pop music.

• They are less likely to select country or rap music than rock music.

• They are more likely to select country music than jazz, classical, or rap music.

• They are certain to select any type of music other than jazz music.

A representative sample of 80 customers in a clothing store was surveyed about how they paid for their purchases. The table shows the responses. Based on the results, which of the following are valid inferences. Select all that apply.

• Tomorrow, 8 out of the first 80 customers will for sure pay with a gift card.

• In a group of 40 customers, it is expected that about 10 will pay with cash.

• About 0.3, or 30%, of all the store's customers will pay with a credit card.

• A sample of 100 customers would provide less reliable data.

Sam tested every 50th candy bar from the assembly line to make sure there were enough peanuts in each bar.  He found 15% did not have enough peanuts.  How many candy bars do not have enough peanuts if the factory produces 20,000 candy bars?

• 300

• 3,000

• 300,000

• 50

The manager of a music store surveyed a random sample of customer who shop in the store about their favorite type of music. The table shows the number of customers who selected each type of music. Based on the information in the table, which inference about the favorite type of music of all the customers who shop in the music store appears to be valid?

• They are certain to select rock or pop music.

• They are less likely to select country or rap music than rock music.

• They are more likely to select country music than jazz, classical, or rap music.

• They are certain to select any type of music other than jazz music.

True or False: all samples lead to a good prediction about an entire population.

• True

• False