With the airing of its fourth episode Tuesday night, NBC’s “Watching Ellie,” starring Julia Louis-Dreyfus, averaged an audience of 9.5 million viewers, a 43-percent plummet from last month’s premiere, according to Nielsen Media Research. Among the advertiser-coveted viewers aged 18 to 49, its rating dropped nearly 50 percent from the show’s Feb. 26 debut. As PEOPLE.com reported earlier this week, before the numbers were in, if the show (on which Louis-Dreyfus, 41, plays a put-upon singer) showed signs of slipping, it most likely would be canceled and add further fuel to the legend of the so-called “Seinfeld” curse. (Her “Seinfeld” costars, Michael Richards and Jason Alexander, both saw their individual follow-up sitcoms suffer early deaths.) Referring to “Ellie,” NBC Entertainment president Jeff Zucker told New York’s Daily News late last week, “If it settles in where it is now, it’s a home run . . . We feel very positive. It’s been a solid performer. Obviously, it’s too early to make any announcements.” On an upbeat note, reports Reuters, “Ellie” held onto about 90 percent of the 18 to 49 audience from its “Frasier” lead-in. In total viewers on Tuesday, “Watching Ellie” ranked third in its 8:30 p.m. time slot, trailing a rerun of CBS’s military drama “JAG” and the Fox premiere of “Andy Richter Controls the Universe,” starring Conan O’Brien’s former sidekick. It was Richter, though, who nabbed the prized 18- to 49-year-olds.