The following table gives the percentages of 15-year-old British boys and girls who are smokers, in a sample of years from 1982 to 2003. Use it to (a) Test, at the 5 percent level of significance, the...

The following table gives the percentages of 15-year-old British boys and girls who are smokers, in a sample of years from 1982 to 2003. Use it to

(a) Test, at the 5 percent level of significance, the hypothesis that the percentage of the boys who smoke is unchanging over time.

(b) Test, at the 5 percent level of significance, the hypothesis that the percentage of the girls who smoke is unchanging over time.

(c) Test, at the 5 percent level of significance, the hypothesis that the percentage of 15-year-olds who smoke is unchanging over time.

Percentage of 15-Year-Old Pupils Who Are Regular Smokers (at least 1 cigarette/week on average), England