Agent's qury! for a newbe!!!!!

Question

hi can some one have a look at theses codes. its for kind of a job interview thing which is due on wed this week. any help would be great.
even just point me in to right direction would be a great help for me. this is a lot of text here..i know, i am sorry.
Write a script to display the average cost for each agent during the months of the year 2000, detailing the average per agent, per month. An agent's cost is determined by the cost of information gleaned by that agent. Create a table called AM_X_443_6 to hold the information with columns NAME (the agent's first and last names), and JAN, FEB, MAR etc to hold the costs. Data should be ordered alphabetically by surname.
here are my tables i am working on:
Agents
CREATE TABLE "john"."AGENTS"
(     "AGENT_ID" NUMBER(8,0) NOT NULL ENABLE,
     "FIRST_NAME" VARCHAR2(50 BYTE),
     "LAST_NAME" VARCHAR2(50 BYTE),
     "CODE_NAME" VARCHAR2(50 BYTE) NOT NULL ENABLE,
     "SECURITY_LEVEL" NUMBER(8,0) NOT NULL ENABLE,
     "BIRTH_DATE" DATE,
     "ACTIVATION_DATE" DATE NOT NULL ENABLE,
     "DEACTIVATION_DATE" DATE,
     "LOCATION_ID" NUMBER(8,0),
     CONSTRAINT "AGENTS_PK" PRIMARY KEY ("AGENT_ID")
locations
CREATE TABLE "john"."LOCATIONS"
(     "LOCATION_ID" NUMBER(8,0) NOT NULL ENABLE,
     "DESCRIPTION" VARCHAR2(50 BYTE) NOT NULL ENABLE,
     CONSTRAINT "LOCATIONS_PK" PRIMARY KEY ("LOCATION_ID")
ACCESS_COST
CREATE TABLE "john"."ACCESS_COST"
(     "COST_ID" NUMBER(8,0) NOT NULL ENABLE,
     "LOWER_BOUND_LEVEL" NUMBER(8,0),
     "UPPER_BOUND_LEVEL" NUMBER(8,0),
     "COST" NUMBER(8,2) NOT NULL ENABLE,
     CONSTRAINT "ACCESS_COST_PK" PRIMARY KEY ("COST_ID")
AM_X_443_6 out come i am looking for
NAME     JAN     FEB     MAR     APR...Dec i.e.

Answer 1

We will split up
1. To get agenat name and his cost details you have to join the two tables
    AGENTS  and ACCESS_COST
  ( But what is the foreign key for Joining these Tables?)
2. To get the sum you have to use th esummary function SUM.
    But since you need sum for each month you have to use SUM(decode(.....
3. For inserting into new table you can use
   insert into ..
   select...