From the chemistry reference sheet, #C=lambdanu# where #C# is the speed of the wave, #lambda# is the wavelength, and #nu# is the frequency. Solving this formula for wavelength, #lambda=C/nu#.
For AM signals, #C=3.0times10^8"m/s"# and #nu# ranges from #550times10^3"Hz"# to #1600times10^3"Hz"# (since #1"kHz"=10^3"Hz"#). Therefore, the wavelength ranges from #lambda=(3.0times10^8"m/s")/(550times10^3"Hz")=545"m"# to #lambda=(3.0times10^8"m/s")/(1600times10^3"Hz")=188"m"#.
For FM signals, #C=3.0times10^8"m/s"# and #nu# ranges from #88times10^6"Hz"# to #108times10^6"Hz"# (since #1"MHz"=10^6"Hz"#). Therefore, the wavelength ranges from #lambda=(3.0times10^8"m/s")/(88times10^6"Hz")=3.4"m"# to #lambda=(3.0times10^8"m/s")/(108times10^6"Hz")=2.8"m"#.