Please help with Audit case

Karina, a first-year auditor, is asked to select a sample of invoices to audit the utility expense account. Below is the account detail.

Month	Balance	Month	Balance
January	$15,245	July	$ 2,901
February	12,973	August	2,837
March	11,359	September	3,690
April	9,326	October	5,890
May	6,380	November	9,823
June	4,558	December	14,906

The audit program asks to select a sample of four items.

Required

1.Using systematic selection, determine which four months will be selected.

2.Using haphazard selection, determine which four months will be selected.

3.Using block selection, determine which four months will be selected.