1A) Chromatogram spectrum - The spectrum is measuring abundance over time.
1B) Spectrum containing peptides - The peaks display an irregular pattern indicating many different peptides present in the same spectrum.
1C) Spectrum containing a protein - The peaks are regularly patterned according to different charge states on a single mass.

2A) X-axis: m/z, Y-axis: intensity or relative abundance
2B) X-axis: m/z, Y-axis: intensity or relative abundance
2C) The peptide that created the peak at 766.40 was isolated and further fragmented (by collision induced dissocation or similar method) to produce a fragmentation scan containing b- and y-ions for that peptide.

3A)

Mass 1: 1126.47/(1126.47-985.78) = 8   (985.78*8)-8 = 7878.24 daltons
Mass 2: 1120.46/(1120.46-980.53) = 8   (980.53*8)-8 = 7836.24 daltons