Have to ask ... why install a 1.9.x? End of life (fixes and security updates) for that version coming in Dec. of this year which isn't that far away.
Have you followed: http://docs.moodle.org/19/en/Installing_Moodle
From the path given to install (/var/www/html/) shall assume operating system is either CentOS or RHEL (or other linux).
Probably best to download the .tar.gz files rather than zips. If you noticed the package sizes on the download page, the zip is larger and probably packaged for Windows machines (has 'extra stuff' not needed on a Linux server).
Have all the php extensions required to run 1.9?
php -v
php -m
First will give version and the second will show the modules of which PHP is aware.
Blank page on installation could be a result of improper permissions on moodle files/folders ... CentOS: as root user and in /var/www/html/
chown apache:apache * -R
Do the same for your data folder, which I assume is in /var/www/
From /var/www/ chown apache:apache moodledata -R
Have you created a blank database for the Moodle?
mysql -u root -p
from mysql> prompt:
create database moodle character set utf8 collate utf8_general_ci;
Check the apache error logs for hints/clues.
/var/log/httpd/error_log
If needing more assistance, please re-post and provide some more specific information ... like remotely hosted? with what provider?, etc.
'spirit of sharing', Ken