Assume the following revenue and cost break-down.

Revenue:

-Monthly membership fee = $30.

Costs:

-General fixed operating expenses = $4,100 per month.

-Equipment Lease = $395 per month.

-Mixed costs are equal to $275 per/month (fixed) plus $1.10 per membership sale (variable).

-Total variable costs are not known.

-Estimated number of members required to break even is 330 members per month.

How to calculate member sales?