$6.$ Long$-$run cost relationships The following graph shows the short$-$run average total cost curves and the long$-$run average cost curve for a publishing firm. The five marked quantities indicate points of tangency between each short$-$run average total cost curve $($ATC$)$ and the long$-$run average cost curve $($

LRAC

$)$; for example,

Q

$1$

$$

marks the point of tangency between

ATC

$1$

$$

and

LRAC

$.$ The orange point on

ATC

$5$

$$

indicates the firm's current output level in the short run

$($Q

$5$

$$

$)$