Is there a relationship between marijuana use and use of other illegal drugs? A survey was conducted in the United States and nine countries in Western Europe. The percentage X of teenagers who have used marijuana and the percentage Y who have used other illegal drugs are as follows: Country % Marijuana % Other Drugs Czech Republic Denmark England Finland Ireland Italy Northern Ireland Norway Portugal United States The correlation between marijuana use and other drug use is calculated to be r = 0.76 and the least squares regression line is calculated to be y = -5.69 + 0.85x. Which of the following statement is true? O a. A good prediction for the percentage of teens who have used other drugs in Scotland (where 73% have used marijuana) is 56.36% O b. About 58% of the variation in other drug use can be accounted for by its regression on marijuana use. O c. It is clear that marijuana is a "gateway drug"; that is, marijuana use leads to use of other illegal drugs because the correlation coefficient is a large positive value. O d. None of the above Clear my choice