Answer:
$6,000
Step-by-step explanation:
Since it is stated in the question that "Typically, the credit card bill is paid in full in the following month", it implies that cash will be disbursed in October for purchases of goods made in September, while cash will be disbursed in November for purchases of goods made in October.
Based on this, Lambert's expected cash disbursement in October for purchases of goods made in September is $6,000, while his expected cash disbursement in November for purchases of goods (a new computer) made in October is $4,500.