For every 3 lemons Chrissy buys at a farm stand,
the total cost increases by $1.80.
The constant of proportionality is ?
An equation that relates the total cost, y, and the
number of lemons, x, is y = ? x.
Use the equation you wrote to complete the table.


Table:

Numbers of lemons(x) | Total cost(y)
4 | _?__
_?__ | $4.20
_?__ | $9.00
18 | _?__