Raja Elected What?

After giving the number of votes polled by Raja Pervez Ashraf and Sardar Mehtab Abbasi respectively, the Madam Speaker announced, “Raja Pervez Ashraf is declared elected as the Prime Minister of the Islamic Republic of Pakistan”.

Could someone more knowledgeable in parliamentary affairs throw light upon the announcement please, that,  was  Raja Sahib not elected as the “Leader of the House” by the MNAs and could become the Prime Minister of the country only after having been sworn in so by the President which ceremony was to take place later that evening in the President House?

Legally speaking, was the announcement of the Madam Speaker correct?

Col. Riaz Jafri (Retd)