Population Inferences

Which of the following would be the BEST definition for the word INFERENCE?

• making a guess about something
• a conclusion reached on the basis of evidence AND reasoning
• creating false presumptions
• summarizing a portion of text

Tags

CCSS.RI.7.1

CCSS.RI.8.1

CCSS.RL.6.1

CCSS.RL.7.1

CCSS.RL.8.1

To evaluate the quality of their product, a manufacturer of cell phones checks every 50th phone off the assembly line. Out of 200 phones tested, 4 are defective. The manager concludes that about 2% of the cell phones produced are defective. Is this conclusion valid?

• Yes

• No

Tags

CCSS.7.SP.A.2

• 273

• 175

• 98

• 77

Tags

CCSS.7.EE.B.3

An online gaming gaming site conducted a survey to determine the types of games people play online. The results are shown in the circle graph. If 1500 people participated in the study, HOW MANY MORE would play card games than arcade games?

• 135 people

• 165 people

• 315 people

• 450 people

Tags

CCSS.7.SP.A.2

A researcher asked five of his doctor friends if they thought the new Brand X medicine that he developed was effective. Four responded "yes." The researcher used the results to write a TV advertisement claiming that "4 out of 5 doctors prefer Brand X medicine." Is this a valid inference? Explain.

• No, because the doctors asked are not a representative sample of the population of doctors.

• No, because 4 doctors said yes out of 9 who were asked.

• Yes, because the doctors asked are a representative sample of the population of doctors.

• Yes, because 4 doctors said yes out of the 5 who were asked.

Tags

CCSS.RI.7.1

CCSS.RI.8.1

CCSS.RL.6.1

CCSS.RL.7.1

CCSS.RI.7.8

Maria collects data from a random sample of 7th graders in her school and finds that 16 out of 20 7th graders participate in after-school activities. How many students should Maria expect to participate in after-school activities if 240 total 7th graders attend Maria's school? Write the numerical answer only.

Tags

CCSS.7.RP.A.3

A movie theater randomly samples the types of admission tickets sold on Friday in the afternoon and the evening. If 400 tickets are sold on a Friday afternoon, use your inference and proportional reasoning skills to determine how many of those 400 tickets would be adult tickets. Type your numerical answer only.

Trinity asked a random sample of 50 students at her school if they brought lunch from home today. If 30 answered “yes,” about what percent of students at Trinity’s school brought lunch from home today?

• 15%

• 30%

• 50%

• 60%

Using your inference skills and proportional reasoning, predict the number of purple jellybeans in a bag of 200 total jellybeans if a random sample of 25 resulted in 4 purple jellybeans. I predict there will be _________ purple jellybeans.

Tags

CCSS.7.SP.A.2

Which size random sample is likely to provide the most trustworthy results?

• 5

• 10

• 30

• There is no difference.

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1