Republican George Bush is studying polling data on prospective running mates that gave Sen. Bob Dole a slight edge over the rest, while Democratic presidential nominee Michael Dukakis blames rising interest rates on "eight years of borrowing and spending, borrowing and spending."

Bush, in Washington, told CBS he jogs and plays horseshoes to help relieve the pressure of preparing for his acceptance speech at next Thursday night's convention session. "I'm no William Jennings Bryan and I think it'll go OK," he said in a reference to the Democratic politician and orator from the turn of the century.The Bush campaign leaked private polling data that said Dole helped Bush more than other potential running mates but by a margin not considered very significant.

A campaign source said the Kansas senator and former rival for the nomination added "a little bit, but not enough to make much of a difference."

The data from Bush's chief pollster, Robert Teeter, were described as all but complete.

Three national polls released Thursday showed Dukakis' post-convention surge had crested. Dukakis' 18-point lead the week after the Democratic convention shrank to 14 points in an NBC News-Wall Street Journal survey conduced Aug. 5-8. A CNN-USA Today poll the same Aug. 5-8 period gave Dukakis a 12-point lead, while a Business Week poll done Aug. 4-9 put the two candidates in a dead heat.

All three of the polls placed support for Dukakis in the 50 percent range, while support for Bush ranged from 36 percent to 45 percent.

The margins of error were three percentage points either way in each poll.

Meanwhile, Dukakis was winding up a quick, five-state campaign trip in Virginia and Florida before flying to Cape Cod for a weekend at the beach.

The Democratic nominee said Thursday's increase in the prime lending rate charged by major banks was "regrettable, but I think it's what happens after eight years of borrowing and spending, borrowing and spending."

Major banks increased their prime rate to 10 percent.

With less than a week to go before he will claim the GOP presidential nomination in the mammoth Superdome, Bush was joining President Reagan for a pre-campaign pep talk to senior administration officials who are expected to fan out across the country this fall to boost Bush.

The vice president planned to fly to New Orleans next Tuesday and have a 15-minute "pass the torch" meeting with Reagan at Belle Chasse Naval Air Station. Reagan was to arrive at the convention city on Sunday and be the star of the show on Monday's opening night.

While remaining in Washington, Bush said he would keep a tight lid on the identity of his running mate until the announcement at the convention.