Which psychographic segmentation approach would be most effective for identifying potential GMAT test-takers who are likely to upgrade to premium services? (difficulty: hard)
In regression analysis, when examining the relationship between advertising spend and sales revenue, what does a p-value of 0.002 for the coefficient indicate? (difficulty: medium)
In forecasting historical data, what does an autocorrelation coefficient of 0.85 at lag 12 typically indicate in monthly business data? (difficulty: medium)