Populations, Samples, and Inferences Review

Anthony opened a new store and wants to conduct a survey to determine the best store hours. Which is the best representative sample?

• A group of randomly selected people who come to the store in one week.

• A group of randomly selected people who visit his website on one night.

• Every person he meets at his health club one night.

• The first 20 people who walk into his store one day.

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

Simon wants to find out which shop has the best frozen fruit drink in town. How could Simon conduct a survey with a sample that is representative of the population?

• Simon could stand outside a popular store in town that does not sell frozen fruit drinks and survey every fifth customer about their favorite local favorite fruit drink shop.

• Simon could stand outside a popular store in town that does sell frozen fruit drinks and survey every fifth customer about their favorite local favorite fruit drink shop.

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

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.

Refer to the data table. Polly surveys two more samples. Do the results from these samples support the inference made from the first sample?

• Yes, the survey results support the inference that doing crafts is the least popular hobby at Polly's school.

• No, the survey results does not support the inference that doing crafts is the least popular hobby at Polly's school.

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

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

The dot plots show how long it took students in Mr. Chauncey's two science classes to finish their science homework last night. Find the means to make an inference about the data.

• The 1st period mean is 35. The 2nd period mean is 38.75. On average, it took students in the 1st period class slightly longer to finish their homework than it did the students in the 2nd period class.

• The 1st period mean is 38.75. The 2nd period mean is 35. On average, it took students in the 1st period class slightly longer to finish their homework than it did the students in the 2nd period class.

• The 1st period mean is 35. The 2nd period mean is 38.75. On average, it took students in the 2nd period class slightly longer to finish their homework than it did the students in the 1st period class.

• The 1st period mean is 38.75. The 2nd period mean is 35. On average, it took students in the 2nd period class slightly longer to finish their homework than it did the students in the 1st period class.

Tags

CCSS.7.SP.A.1

CCSS.7.SP.A.2

CCSS.7.SP.B.4