Making Inferences from a Random Sample

Marcus and Rafael live in two different neighborhoods. They both conduct a random sample of 25 people to survey favorite sports in their neighborhood. The results are in each of the polls. Which of the following is a valid conclusion?

• People that live in Marcus's neighborhood prefer to play basketball more than the people in Rafael's neighborhood.

• Swimming is the least favorite sport in both neighborhoods.

• People in Marcus's neighborhood prefer to play soccer, while people in Rafael's prefer to play basketball.

• People in both neighborhoods don't like to swim because the weather is too cold.

A random sample of 6th and 7th grade students at Ford Middle School were asked how much time they spend on homework each night in each class. Which of the following is valid comparison?

• 7th graders have 5 more minutes of science homework each night than 6th graders.

• 7th graders have 15 more minutes of homework each night than 6th graders.

• 6th and 7th graders spend the most time on math and language arts homework because those are the hardest subjects for every student.

• 6th grade students spend the least amount of time on social studies homework because they complete most of it in class.

Tags

CCSS.6.RP.A.3A

A random sample of freshman at University of Dallas (UTD) and the University of North Texas (UNT) were polled about their summer vacation activity plans. Which of the following is a valid comparison?

• Only 50 students were polled at UTD, while 100 students were polled at UNT.

• If you polled 100 students at both schools, you could expect the same number of students to visit friends at UTD as students that travel with family at UNT.

• Less people are working at both schools over the summer because they are taking summer schools classes.

• There are twice as many students that are working over the summer at UTD than at UNT.

Roger polled 18 classmates to find out the average number of hours each spend online each week. Based on the results he finds that one-third of students spent 15-19 hours inline each week. Which of the following graphs could be the poll of data used?

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The bar graph below shows the number of boys and girls enrolled in each foreign language class at RISD high school. Which of the following statements in a reasonable inference?

• The same number of boys and girls are enrolled in German.

• The number of girls taking Spanish is three times the number of girls taking Chinese.

• More students are enrolled in Spanish because more students want to travel to Spain.

• More girls are enrolled in foreign language across the district than boys.

The chart below shows the number of students in Mrs. Johnson's 1st period class who were born during each month of the year.

• More students were born during the first six months than during the last six months.

• More students were born in January and February than in September, October, November and December.

• The median number of students born each month is 5.5.

• The greatest number of students born in 1 month is 4.

Tags

CCSS.4.MD.B.4

Mr. Dan surveyed the students in his science class about the type and number of pets they owned. Which circle graph might best represent the student population?

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The graph below shows the average number of goals the local hockey team scored during each part of its games the first 10 games of the season. Which of the following is a valid inference?

• The team scores the most goals during 1st period because they have the most energy at the start of the game.

• The team scores more goals during the 1st period than the other two periods combined.

• 25% of the team's goals are scored in the 2nd period.

• If the team were to score 40 goals, you would expect 10 of them to occur in overtime.

What inference can you draw from this survey?

• I can infer that most students in this school like pizza.

• I can infer that very few students like hamburgers.

• I can infer that their favorite is corn dogs.

• I can infer that most students in this school like hamburgers.