Figure I below shows the visible part of the emission spectrum from hydrogen gas in a laboratory on the Earth. The numbers indicate the wavelength, in 
, represented by each line.
I
The same part of the emission spectrum from hydrogen as in Figure I above, observed in light from stars in a distant galaxy, is shown in Figure II below. The numbers indicate the wavelengths in .
II
The spectrum shows the same pattern as Figure I but with different wavelengths.
Use one of the lines in Figure I and the corresponding line in Figure II to determine the speed of the distant galaxy relative to the observer.
The galaxy is known to be a distance of 
from the Earth. Use your answer in (a) to determine a value for the Hubble constant 
.
.
.
