Population, Sample and Inferences

At a middle school, the 7th graders will conduct a survey for where to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year
• to randomly choose some 7th grade students to select a location
• to ask all 7th grade teachers and administrators for a location
• to ask the student council to choose a location

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

Interview the first 30 students who enter the school in the morning. 

• simple random
• population
• systematic
• convenience

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She picks the student in every 5th seat.

• Simple Random
• Systematic 
• Unbiased
• convenience

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

At a middle school, the 7th graders will conduct a survey for where to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year
• to randomly choose some 7th grade students to select a location
• to ask all 7th grade teachers and administrators for a location
• to ask the student council to choose a location

The Candlelit-Dinner Candle Store surveys its Monday customers to find out their opinion on a new scented candle.  Is this biased or unbiased?

• Biased
• Unbiased

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

A teacher decides to survey the students in her classes to find out their opinion on the new menu in the cafeteria.  Is this biased or unbiased?

• Biased
• Unbiased

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

Becky wants to know if she should sell cranberry muffins at her bakery. She asks every customer who buys blueberry muffins if they would buy cranberry muffins. Is this a representative sample?

• Yes, it does not include people who would buy cranberry muffins but do not like blueberry muffins

• No, it does not include people who would buy cranberry muffins but do not like blueberry muffins

• Yes, it does include people who would buy cranberry muffins but do not like blueberry muffins

• No, it does include people who would buy cranberry muffins but do not like blueberry muffins

Tags

CCSS.7.SP.A.1

There are 400 students at Polly's school. She surveyed a random sample of 80 students to find their favorite hobby. 19 said they like to read. 30 said they like to be with friends. 8 said they like to do crafts. 23 said they like to play sports. Polly infers that doing crafts is the least popular hobby at her school.

Yovani estimates that about 200 students in the school favor playing sports as a hobby. Do you agree?

• Yes, I used a proportion to find the number of students in the school who likely to prefer to play sports. 23/80 = 200/400; 200 students

• No, I used a proportion to find the number of students in the school who likely to prefer to play sports. 23/80 = 115/400; 115 students

Tags

CCSS.7.RP.A.2

CCSS.7.RP.A.3

CCSS.7.SP.A.1

CCSS.7.SP.A.2

The two data sets show the number of days that team members trained before a 5k race. What inference can you draw by comparing the median?

• There is more variability in the number of days that Team A members trained because the IQR for Team A is greater than the IQR for Team B.

• There is more variability in the number of days that Team B members trained because the IQR for Team B is greater than the IQR for Team A.

• Team A members generally trained for more days than Team B members

• Team B members generally trained for more days than Team A members

Tags

CCSS.7.SP.B.4

What inference can you draw by comparing the interquartile ranges?

• There is more variability in the number of days that Team A members trained because the IQR for Team A is greater than the IQR for Team B.

• There is more variability in the number of days that Team B members trained because the IQR for Team B is greater than the IQR for Team A.

• Team A members generally trained for more days than Team B members

• Team B members generally trained for more days than Team A members

Tags

CCSS.7.SP.B.3

CCSS.7.SP.B.4