Jim is absolutely correct is stating that the standard printer resident 'LinePrinter' font is a bitmap font, and is hence only available in the one fixed size.
It would be selected using something like:
<esc>(0N<esc>(s0p16.67h8.5v0s0b0T
(depending on which symbol set is required - 19U (the Windows ANSI set) is not available with this font).
The thread title is:
"Can the Line Printer font be sized??"
but the question in the initial text is:
"Can the cpi of this font be adjusted?"
The size of the font cannot be changed (as explained by Jim, and paraphrased above) but if all that is required is an adjustment to the Characters Per Inch (horizontal spacing), this can be achieved by using the 'Set Horizontal Motion Index' sequence:
<esc>&k#H
where # represents the required character spacing in 1/120 inch units.
This only works with fixed-pitch fonts (LinePrinter is one); with proportionally-spaced fonts, it only affects the width of the space character.