Proportions

Population data

Sample data

A known population proportion

A random sample

Larger sample sizes have no effect on the width of confidence intervals for proportions.

It variably affects width depending on whether or not outliers are present in larger samples.

It increases width due to greater variability introduced by more data points.

It reduces the width making it more precise because standard error decreases with larger sample sizes.

To guarantee that all subgroups are equally represented in the sample size.

To minimize bias in estimating the population parameter.

To justify using different types of statistical tests on collected data sets.

To ensure that there are no outliers in the collected data set.

Interquartile range

Variance

Standard error

Range

They eliminate the need for any further data collection since they yield total certainty about the population proportion.

They give exact values for future sample proportions resulting from the same population.

They provide a range within which the true population proportion is likely to lie with a measured degree of confidence.

They ensure that the sample proportion will always match the center of the interval exactly.

A value indicating a population proportion of about 0.18

A value suggesting a population proportion of exactly 0.20

A value implying a population proportion less than 0.25

A value in the sample that suggests a population proportion greater than 0.30

Wider confidence intervals always lead to more accurate conclusions about population characteristics than narrower ones even if overlap occurs.

Narrower intervals have no effect on claims because they simply reflect less variability within sample data points around an estimate.

Narrower intervals increase precision but reduce certainty in claiming differences or similarities between populations due to smaller margins of error.

The sample proportion is an accurate estimate of the population proportion

The sample is representative of the population

The confidence level is high

The true population proportion is within the estimated range

Larger samples decrease width whereas higher certainty increases it, resulting in offsetting effects depending upon the magnitude of each change.

Smaller widths result solely from increasing certainty, disregarding alterations made concerning the number of individuals surveyed.

Wider spans arise from augmenting figures under scrutiny yet diminish elevating levels of certainty surrounding the estimate.

Neither modification exerts influence over the breadth of computed intervals given that they are unaffected by these particular parameters.

Asking for expert opinions.

A census of the entire population.

Voluntary response sampling.

Random sampling.