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?
- Grade 7 is higher, because 6.2 hours is more than 5.8 hours.
- The two are equal, because the intervals overlap.
- We can't be sure which is higher: the intervals overlap.
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?
- The two are equal, because the intervals overlap.
- We can't be sure which is higher: the intervals overlap.
- Oak School is higher, because 50% is more than 44%, so the gap is real.
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?
- 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?
A random sample of 400 of Noah's school's 2400 students found 25% play an instrument, margin of error 4 percentage points. How many more students is the highest estimate than the lowest?
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?
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?
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?
From a random sample, Ari's report says 31% to 39% of all students visit the library each week. That is the sample result ± the margin of error. What is the margin of error?
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?
