Sample Proportion
Definition
The sample proportion is the ratio of the number of successes in a sample to the total number of observations in that sample.
Analogy
Imagine you have a bag of 100 marbles, and you want to know what proportion of them are red. You randomly select 20 marbles from the bag and find that 5 of them are red. The sample proportion would be 5/20 or 0.25, meaning that approximately 25% of the marbles in your sample are red.
Related terms
Random Sampling: Random sampling is a method where each member of a population has an equal chance of being selected for inclusion in a sample.
Confidence Interval: A confidence interval is an estimate range within which we believe the true population parameter lies with a certain level of confidence.
Margin of Error: The margin of error is the maximum amount by which our estimate might differ from the true population parameter.
"Sample Proportion" appears in:
Additional resources (1)
Practice Questions (9)
What condition must be satisfied in order for us to assume that the sampling distribution of the sample proportion is approximately normal?
If the true population proportion is 0.3, what is the center of the sampling distribution for the sample proportion?
If the population proportion is 0.3 and the samples taken from the population are of size 40, what can be said about the shape of the sampling distribution for the sample proportion?
If the sample drawn from the population is of size 100 and the true population proportion is 0.38, what is the standard deviation of the sampling distribution for the sample proportion?
If the mean of the sampling distribution for the sample proportion is 0.59, what is the true population proportion?
Why do we divide the variances of each sample proportion by their sample size before finding the overall standard deviation?
How can we check that the sampling distribution of a sample proportion is approximately normal?
To calculate the z-score in a one-proportion z-test, we compare the observed value, which is the sample proportion, to:
If you conduct a two-sided one-proportion z-test and calculate the z-score of the sample proportion to be -1.235, what is the p-value?
Resources
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