A student wants to estimate the proportion of people who prefer tea over coffee in her country. She surveys 120120 members of her university's tea club and finds that 110110 prefer tea. She constructs a 95%95\% confidence interval for the proportion of tea-preferring people in the country. What is the error in her approach?

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1. Introduction to Statistics(0)

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Visualizing Qualitative vs. Quantitative Data
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Frequency Distributions
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Sampling Distribution of the Sample Mean and Central Limit Theorem
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Introduction to Confidence Intervals
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Confidence Intervals for Population Mean
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Determining the Minimum Sample Size Required
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8. Sampling Distributions & Confidence Intervals: Proportion(0)

Sampling Distribution of Sample Proportion
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Confidence Intervals for Population Proportion
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Chi Square Distribution
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Confidence Intervals for Population Variance
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8. Sampling Distributions & Confidence Intervals: Proportion

Confidence Intervals for Population Proportion

8. Sampling Distributions & Confidence Intervals: Proportion

Confidence Intervals for Population Proportion: Videos & Practice Problems

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Problem 143Multiple Choice

A student wants to estimate the proportion of people who prefer tea over coffee in her country. She surveys $120$ members of her university's tea club and finds that $110$ prefer tea. She constructs a $95 percent sign$ confidence interval for the proportion of tea-preferring people in the country. What is the error in her approach?

The sample is not representative of the country's population, so the confidence interval is not valid.

The sample size is too small for inference.

She should have used a lower confidence level.

The calculation should be based on the mean, not the proportion.

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