For many countries tourism is an important source of revenue. Data are collected on the number of foreign visitors to a country (in millions) and total tourism revenue (in billions of dollars) for a sample of 10 countries. The regression equation fit was Tourism ($ bill) = 21.5 + 0.295 Visitors (mill). If we were interested in predicting the tourism revenue for a particular country that had 30 million foreign visitors, what process should be used?
A. We should not use this equation because it is not significant.
B. We should use the standard error.
C. We should construct a confidence interval using this equation.
D. We should construct a prediction interval using this equation.
C. We should use the correlation.