Analyzing Survey Data Reliability

00:00 10 marks

A team of researchers is conducting a survey to estimate the average daily consumption of sugar-sweetened beverages among adolescents. To ensure the sample accurately represents the population and minimizes bias, a specific sampling procedure is required. Based on this scenario, answer the following questions:

Part a

4 minutes 4 marks

Question

Describe a detailed sampling procedure that could be used to reduce bias and improve the reliability of the estimated average consumption of sugar-sweetened beverages among adolescents.

Hint Hint

Hint

Think about stratified or cluster sampling to ensure representation from all relevant subgroups within the adolescent population.

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Complete Answer

An appropriate sampling procedure is stratified random sampling. This involves dividing the adolescent population into distinct strata based on relevant characteristics such as age group, geographical location, or socio-economic status. Random samples are then drawn from each stratum, ensuring proportional representation from all subgroups.

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Part b

6 minutes 6 marks

Question

The survey results indicate an average daily consumption of 2.5 servings of sugar-sweetened beverages, with a 95% confidence interval of (2.3, 2.7) servings. Interpret this confidence interval and discuss what it implies about the reliability of the survey estimates.

Hint Hint

Hint

Consider the meaning of a confidence interval in terms of estimation precision and the implications for potential sampling errors.

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Complete Answer

The 95% confidence interval (2.3, 2.7) means we can be 95% confident that the true average daily consumption of sugar-sweetened beverages for all adolescents lies within this range. The narrow width of the interval (only 0.4 servings) suggests a precise estimate, indicating high reliability, assuming the sampling method was unbiased and representative.

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