In hypothesis testing, what does the analyst do?

In hypothesis testing, what does the analyst do?

• A. Tests expectations through experience and decides between null and alternative
• B. Calculates a confidence interval
• C. Determines a mandatory sample size
• D. Predicts a single future observation

Answer: (A)

Hypothesis testing is about using sample data to assess whether a claimed population parameter is plausible. The analyst evaluates the observed data against the null hypothesis and makes a decision about whether the evidence is strong enough to reject the null in favor of the alternative, usually using a test statistic and a significance level. This approach captures the core activity: testing expectations derived from data and deciding between the null and the alternative. The other activities described don’t fit the main task of hypothesis testing: estimating parameters with a confidence interval focuses on estimation rather than testing a hypothesis; planning or determining a sample size is about study design; predicting a single future observation is about forecasting, not testing a population statement.

Hypothesis testing is about using sample data to assess whether a claimed population parameter is plausible. The analyst evaluates the observed data against the null hypothesis and makes a decision about whether the evidence is strong enough to reject the null in favor of the alternative, usually using a test statistic and a significance level. This approach captures the core activity: testing expectations derived from data and deciding between the null and the alternative.

The other activities described don’t fit the main task of hypothesis testing: estimating parameters with a confidence interval focuses on estimation rather than testing a hypothesis; planning or determining a sample size is about study design; predicting a single future observation is about forecasting, not testing a population statement.