Estimate a population from a sample survey, with the margin of error given
Grade 9 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.
Esme compared random-sample surveys of weekly reading time. Grade 7: 6.2 hours, margin of error 0.5. Grade 8: 5.8 hours, margin of error 0.6. Which conclusion fits?
- The two are equal, because the intervals overlap.
- We can't be sure which is higher: the intervals overlap.
- Grade 7 is higher, because 6.2 hours is more than 5.8 hours.
Jun compared random-sample surveys of percent who bike to school. Oak School: 50%, margin of error 5 points. Elm School: 44%, margin of error 6 points. Which conclusion fits?
Two number lines, one above the other, each with a dot at its sample result (50% and 44%) and a bar for its margin of error (not to scale). Two number lines, one above the other, each with a dot at its sample result (50% and 44%) and a bar for its margin of error (not to scale). Oak School 0 10 20 30 40 50 60 70 80 90 100 margin of error 50% % Elm School 0 10 20 30 40 50 60 70 80 90 100 margin of error 44% % - Oak School is higher, because 50% is more than 44%, so the gap is real.
- The two are equal, because the intervals overlap.
- We can't be sure which is higher: the intervals overlap.
Kira compared random-sample surveys of nightly sleep. The chess club: 7.9 hours, margin of error 0.3. The art club: 7.1 hours, margin of error 0.4. Which conclusion fits?
Two number lines, one above the other, each with a dot at its sample result (7.9 hours and 7.1 hours) and a bar for its margin of error (not to scale). Two number lines, one above the other, each with a dot at its sample result (7.9 hours and 7.1 hours) and a bar for its margin of error (not to scale). 7.9 hours 0 1 2 3 4 5 6 7 8 9 10 Not to scale. 7.1 hours 0 1 2 3 4 5 6 7 8 9 10 Not to scale. - The art club is likely higher, because its margin of error is much bigger than the chess club's.
- We can't tell, because a sample is never exact.
- The chess club is likely higher: even its lowest estimate is above the art club's highest.
Luz compared random-sample surveys of percent who bring lunch from home. Pine School: 65%, margin of error 5 points. Lake School: 48%, margin of error 6 points. Which conclusion fits?
Two number lines, one above the other, each with a dot at its sample result (65% and 48%) and a bar for its margin of error (not to scale). Two number lines, one above the other, each with a dot at its sample result (65% and 48%) and a bar for its margin of error (not to scale). 0 10 20 30 40 50 60 70 80 90 100 65% 0 10 20 30 40 50 60 70 80 90 100 48% - We can't tell, because a sample is never exact.
- Lake School is likely higher, because its margin of error is bigger.
- Pine School is likely higher: even its lowest estimate is above Lake School's highest.
A random sample of 300 of Milo's school's 1500 students found 40% walk to school, margin of error 6 percentage points. How many more students is the highest estimate than the lowest?
Number line with a dot at the sample result, 40%, and a bar for the margin of error (not to scale; its ends are not labeled). Number line with a dot at the sample result, 40%, and a bar for the margin of error (not to scale; its ends are not labeled). margin of error 40% Not to scale. A random sample of 120 of Pia's school's 600 students averaged 4.5 books read last month, margin of error 0.4. How much greater is the highest estimate of the school's total than the lowest?
Number line with a dot at the sample result, 4.5, and a bar for the margin of error (not to scale; its ends are not labeled). Number line with a dot at the sample result, 4.5, and a bar for the margin of error (not to scale; its ends are not labeled). 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 margin of error sample result Not to scale. A random sample of 100 of Ren's school's 900 students averaged 2.5 hours of homework a week, margin of error 0.3. How much greater is the highest estimate of the school's total than the lowest?
Number line with a dot at the sample result, 2.5, and a bar for the margin of error (not to scale; its ends are not labeled). Number line with a dot at the sample result, 2.5, and a bar for the margin of error (not to scale; its ends are not labeled). 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 margin of error sample result Not to scale. From a random sample, Tala's report says 52% to 64% of all students want a garden club. That is the sample result ± the margin of error. What is the margin of error?
Number line with a bar from 52% to 64%; the middle of the bar is not marked (not to scale). Number line with a bar from 52% to 64%; the middle of the bar is not marked (not to scale). 60 bar Not to scale. From a random sample, Zee's report says the students' mean outdoor play is 5.4 to 6.2 hours a week. That is the sample mean ± the margin of error. What is the margin of error?
Number line with a bar from 5.4 to 6.2; the middle of the bar is not marked (not to scale). Number line with a bar from 5.4 to 6.2; the middle of the bar is not marked (not to scale). 5 5.2 5.4 5.6 5.8 6 6.2 6.4 6.6 6.8 7 Not to scale. From a random sample, Bo's report says the students' mean bus ride is 17.5 to 21.5 minutes. That is the sample mean ± the margin of error. What is the margin of error?
Number line with a bar from 17.5 to 21.5; the middle of the bar is not marked (not to scale). Number line with a bar from 17.5 to 21.5; the middle of the bar is not marked (not to scale). not to scale 16 17 18 19 20 21 22 23