Shares of Dollar General Corp. tumbled 7.4% in premarket trade Thursday, after the discount retailer reported a fiscal first-quarter profit and sales that rose less than expected. Net income for the quarter to May 4 rose to $364.9 million, or $1.36 a share, from $279.5 million, or $1.02 a share, in the same period a year ago, as the tax rate declined to 21.6% from 37.2%. The FactSet consensus for earnings per share was $1.40. Revenue increased 9.0% to $6.11 billion, below the FactSet consensus of $6.18 billion, as same-store growth of 2.1% missed expectations for a 3.2% rise. The company said it faced a “significant weather-related headwind” during the quarter. The company affirmed its outlook for 2018 revenue growth of 9%, a same-store sales increase in the mid-2% range and EPS of $5.95 to $6.15. The stock had gained 3.8% year to date through Wednesday, while the SPDR S&P Retail ETF had advanced 4.6% and the S&P 500 had edged up 1.9%.