Harold invested $30,000 in various stocks
and bonds. He earned 6% on his bonds
and 12% on his stocks. If Harold's total
profit on both types of investments was
$2,460, how much of the $30,000 did he
invest in bonds?

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .