measures of variability 7th grade

What two types of samples give you the best data for a population?

• Simple Random Sample

• Convenience Sample

• Voluntary Response Sample

• Systematic Response Sample

The principal at Key North Middle School wants to determine if the 85 students in the 7th grade prefer to collect bottles or sell magazines as their year-end trip fundrasier. Select ALL the sets of people that could be a representative sample of the population.

• 10 sixth-grade students, 10 seventh-grade students, 10 eighth-grade students

• 40 students from the school

• 30 seventh-grade students

• 10 seventh-grade boys and 10 teachers

• 15 seventh-grade boys and 15 seventh-grade girls

Tags

7.SP.1

What are the Measures of Center?

• Mean

• Median

• Mode

• Range

• Interquartile Range

What do the box plots tell you about the variability of the data?

• B has greater variability because its range and IQR are greater than A.

• B has greater variability because its median & mean are greater than A.

• A has greater variability because its range & IQR are greater than B.

• A has greater variability because its median and mean are greater than B.

Tricia surveys students in her computer class about time spent on computers by students in her school. Is this a representative sample? Explain.

• No; Only a few students in the school take computer class.

• No; Students in computer class likely use computer more than other students.

• Yes; Students in computer class are representative of the school.

• Yes; Students in computer class are representative of people in the town

What is the range of the data shown?

• 85
• 90
• 80
• 70

Which student has the greater range of test scores?

• Amy

• Ed

Students were surveyed about their favorite type of book. 25% of students said their favorite book was mystery. If there are 250 students in the school, predict how many would choose mystery as their favorite book?

• 25

• 10

• 63

• 1,000

Data from a survey asking students about the number of siblings in their families are shown. Compare the mean data.

• Students in 6th grade have 5 more siblings

• Students in each grade have a similar number of siblings

• Students in 7th grade have fewer siblings

• There is no difference in the number of siblings by grade

What is the best measure of center for this data set:

95, 95,95,95,95,95,95,70

• mean

• median

• mode

• average