The pay-as-you-go mobile phone carrier plunged on a second-quarter profit of 24 cents a share, missing estimates. The company said net income rose to $84.3 million, up from $79.9 million, or 22 cents per share, in the same period a year earlier. Revenue rose 19 percent to $1.21 billion from $1.01 billion. Analysts expected 28 cents on revenue of $1.22 billion. MetroPCS has about 9.1 million subscribers.