(1)答:这一幅复式条形统计图.
(2)8+18+5+3+2=36(人)
或17+11+4+1+3=36(人)
答:这个班共有学生36人.
(3)
×100%8 36
≈0.222×100%
=22.2%,
×100%36?2 36
=
×100%34 36
≈0.944×100%
=94.4%;
×100%17 36
≈0.472×100%
=47.2%,
×100%36?3 36
=
×100%33 36
≈0.917
=91.7%.
答:语文优秀率是22.2%,及格率是94.4%;数学优秀率是47.2%,及格率是91.7%.
故答案为:复式条形,36,22.2%,94.4%,47.2%,91.7%.