Table $8\mathrm{.}7$

The Universal Computer Company wants to forecast the monthly sales of their newly introduced tablet computer using the following historical sales data:

Month Sales $($units$)$

$18,000$

$210,000$

$312,500$

$411,000$

$510,500$

$611,500$

$711,000$

Use the information in Table $8\mathrm{.}7.$ What is the forecast for period $8$ using a naive forecast?

$10,800$

$11,250$

$11,000$

$10,500$