Non-college-bound high-school seniors are times more likely to smoke at least half a pack of cigarettes a day than college-bound high-school seniors.

three times

Explanation:

According to research, non-college-bound high-school seniors are three times more likely to smoke at least half a pack of cigarettes a day than college-bound high-school seniors.

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.