Inference for a Population Proportion
Confidence Interval & Significance Test
Find Sample Size
Enter Data:
From Textbook
Number of Successes
Individual Observations
Choose Dataset:
Protect Environment
Influenza Vaccine
COVID-19 Infections
Fracking
Death Penalty
Stem Cell Research
E. Coli in Chicken Breasts
Sample Size:
# of Successes:
Select Labels for Success/Failure
Success:
Failure:
Enter individual observations, separated by a space. Or, copy & paste values from spreadsheet:
Which category defines a success?
Yes
No
Type of Inference:
Confidence Interval
Significance Test
Confidence Level:
Interval, Lower or Upper Bound?
Interval
Lower
Upper
Null Value p
0
:
Alternative:
Two-Sided
Less
Greater
Options:
Show z-score for Margin of Error
Select Range of x-Axis
Select Lower and Upper Limit:
Type of Confidence Interval:
Wald
Agresti-Coull
Wilson Score
More Info on Dataset
Barchart
Plot of Interval
Distribution of
Sample Proportion
Decision Reject/Not Reject
Significance Level (in %)
More Info on Dataset
Barchart
Plot of P-value
Here, you can find the sample size necessary to achieve a desired margin of error for your confidence interval.
Desired Confidence Level:
Desired Margin of Error:
Use Conservative Approach (p=0.5)
Provide Guess for Population Proportion p:
Options:
Interval, Lower or Upper Bound?
Interval
Lower
Upper
Plot Sample Size vs. Margin of Error
Range for Margin of Error:
to