Assumptions (Conditions) for making a Confidence Interval

One-population Mean Assumptions

• Quantitative Data,Random Sample

• Individuals Independent

• data is normal or n = 30

One-population Proportion Assumptions

• Categorical, Random Sample(s)

• Individuals Independent

• 10 successes and 10 failures

Bootstrap Confidence Intervals

• Random Sample(s)

• Individuals Independent

One-Population Variance or Standard Deviation Assumptions

• Quantitative data, random
• Data within the should be independent.
• normal.

Two-population Mean Assumptions (Matched Pair)

• Quantitative data, random
• Data within sample is independent.
• At least 30 pairs or have normal shape.

Two-population Mean Assumptions (Not Matched Pair)

• Quantitative samples, random
• Data within samples is independent.
• Data between is independent.
• n = 30, near normal shape

Two-population Proportion Assumptions

• Categorical samples, random
• Data within samples is independent
• Data between samples is independent
• 10 successes, failures

Bootstrap and Randomized Simulation Assumptions

• sample data is random
• Data within is independent
• If multiple samples were collected that were not matched pair, then the data values between the samples
should be independent of each other.