You've got the solution to the problem: you need to store the form data.
Now, judging by the fact you're asking the question, you're probably not sure which way to store it.
You've got three main (read: sensible) ways: Cookies, Sessions, and Database.
Database is the secure and highly scalable option, but you'll need to invoke sessions to do it. Doesn't sound like the optimal choice for your situation.
Cookies are fun, but they are dependent on cookies being enabled by the host machine (as are sessions, frankly, to an extent).
Sessions are probably going to be your best bet.
Here's a good looking tutorial that should tell you just how to store this information from one page to another:
http://www.tizag.com/phpT/phpsessions.php
Your adaptation in a nutshell (but read the tutorial before you try to analyze this):
PHP Code:
session_start();
// On page 1
$_SESSION['mySurvey'] = array( "data" => array() ); // Create an array to put our data in. We'll use the format $_SESSION['mySurvey']['data']['survey_one']
// Pages 1 through final
// Now let's say you've only got one question on this page and the answer is stored in $answer.
// Let's make our result array
$results = array( "Question could go here as the key" => $answer );
// Now store your results in the session
$_SESSION['mySurvey']['data']['survey_one'] = $results;
Then, on the final page, you can iterate over your results (possibly using a
foreach loop, and then format it however you'd like.
Before you post, read our: 
Combining multiple forms to send in one E-mail
