Mariah Carey (Michael Buckner/GETTY IMAGES FOR BET)

It’s official — Mariah Carey’s in, and Jennifer Lopez is out as chick judge on “American Idol,” Fox programming chief Kevin Reilly officially announced Monday at Summer TV Press Tour 2012.

Going for high drama, Reilly kicked off his Q&A session by dialing some phone number on his cell phone while blah, blah, blah-ing about the “artist that many of these [‘Idol’] contestants have tried to emulate, have tried some of the songs, have tried to hit the notes” who the network had just signed in the last few hours.

“It would be funny if I got the [answering] machine, wouldn’t it?” Reilly said as he fumbled around trying to make the call and reporters waited to see if it was some lame gag.

“Hi, Mariah? How are you? It’s Kevin,” he said. “We do have the deal don’t we? Yes!”

“I am so excited to be joining ‘Idol,’ Carey told all 200-plus TV critics attending in the Beverly Hilton ballroom in Beverly Hills, via Reilly’s cell phone, after he put her on speaker phone, and held his phone up to the microphone attached to his shirt front. Very band-aid and chewing gum.

She said she wished she could have been with them, but “this kind of all just happened really quickly” — though it had been reported for the past couple of weeks that she was in negotiations to replace J-Lo for a reported salary of nearly $18 mil a year.

Carey, Reilly gloated, is “the biggest recording artist that any of these shows has ever had.” (In its announcement, Fox noted Carey has sold more than 200 million records worldwide; has more No. 1 songs than any solo artist in history; and has 18 Billboard No. 1 singles — 17 of which Carey wrote — behind only The Beatles.)

“I heard Nigel say that 99 percent thing,” in re JLo, he said of “Idol” producer Nigel Lythgoe having said, just moments earlier at the tour, that JLo said she was “99 percent” certain she was leaving the singing competition.

“I think I can say it’s 100 percent Jennifer won’t be back to the show,” Reilly grinned.

Bye-bye, JLo!

“I can’t confirm and don’t want to talk about anyone” else on the show, Reilly said on stage, anticipating questions about third judge Randy Jackson, or a replacement for judge Steven Tyler.

On the other hand, Reilly did say Jackson, the show’s only surviving original judge, “has been working with Mariah, and is in fact her co-manager, and…was very instrumental in doing this deal.”

Translation: Randy’s safe.

Nice work, Randy!

After the most recent season of “Idol” wrapped in May with its least watched season finale ever, various Fox and parent-company suits said they had been too complacent about the important franchise that season, and that major changes were in store.

Despite the declines, “Idol” wound up the season as the country’s most watched show after NBC’s Sunday football.

Since then, Tyler announced he’s “decided it’s time for me to let go of my mistress ‘American Idol’ before she boils my rabbit,” and JLo did too — or words to that effect — no matter what Lythgoe tells you.

Carey, being one of the music industry’s best-selling pop stars, will give “Idol” an edge in the increasingly crowded singing competition arena, Reilly boasted.

He’s talking about Fox’s other singing show, “X Factor” which recently signed popsters Britney Spears and Demi Lovato as judges, and NBC’s “The Voice,” which boasts Christina Aguilera, Adam Levine, Blake Shelton and Cee Lo Green as its judges.

“Not being the only game in town now, we need to keep things fresh,” Reilly said, saying they’ll get another star to replace Tyler.

Speaking of “X Factor,” its creator of course had something to say about “Idol’s” announcement.

“I think she’s going to find it difficult to say ‘no.’ You’ve got to say ‘no’ to people [on these shows] and she’s sweet,” “X Factor’s” Simon Cowell (the former “American Idol” judge) said of new “Idol” judge Carey during his Fox singing competition’s Q&A session Monday afternoon.

Then Cowell must have remembered that Carey’s husband, Nick Cannon, is host of his “America’s Got Talent” show on NBC, because he corrected himself and said: “No — I think she’ll be great.” Cowell added: “I was with her this week, so I knew it was going to happen.”

Because, of course, it’s all about Simon.

As for replacing Tyler, Reilly bragged: “We have the biggest names in the business.” And over the next couple of weeks, he said, “it will be a matter of picking the right one, with the right chemistry, making the deal, and finalizing it.”

Earlier in the day, the Fox singing competition’s exec producer Nigel Lythgoe told TV critics, “I can’t make any comment with regard to my future on ‘American Idol’,” explaining he’s currently in contract negotiations.

Lythgoe, up on stage to talk about Fox’s dance competition “So You Think You Can Dance,” on which he’s one of the judges, said he was “really upset to hear of Steven [Tyler] leaving us, and the possibility of Jennifer [Lopez] leaving us,” he said of two of “Idol’s” three judges.

On the other hand, he also said in a scrum immediately after the Q&A session that he thought “Idol” should have new judges every year.

He also insisted JLo was only “99 percent out on the show. “She did say 99 percent – that’s a strange thing to say, 99 percent,” Lythgoe said. “You’re either leaving, or not. I’m hoping that one percent means she’s not leaving.”

The disingenuous son of a gun.

Lythgoe had been quoted the other day saying the show was talking to Charlie Sheen and Jerry Lewis about becoming judges. During his “DWTS” Q&A session Monday, he explained, there were “thousands” of names being rumored as possible “Idol” judge replacements at that time, and “I tried to deflate everything by saying the Three Stooges.”

Tyler, Lopez and Randy Jackson on “Idol.” (Michael Becker/AP)