After certification of the application, a petition containing a summary of the subject matter shall be prepared by the lieutenant governor for circulation by the sponsors. If signed by qualified voters who are equal in number to at least ten per cent of those who voted in the preceding general election, who are resident in at least three-fourths of the house districts of the State, and who, in each of those house districts, are equal in number to at least seven percent of those who voted in the preceding general election in the house district, it may be filed with the lieutenant governor.