If you're still confused about the new federal tax law, you're in good company. Fifty professionals who advertise themselves as experts calculated a mythical family's taxes and came up with 50 different answers.

Even worse, according to a survey by Money magazine, the experts' figure for the family's tax bill varied from $12,539 to $35,813. The correct answer, according to the accountant who devised the test, was $23,393."The abundance of mistakes our test turned up suggests that pros are nowhere near as knowledgeable about the tax law as they are supposed to be," Money writes in its March issue. "After all, we were sampling highly regarded preparers who willingly accepted our challenge to calculate the model return."

The experts actually did worse than in a similar Money test a year ago, when taxpayers were facing effects of the landmark 1986 tax law for the first time.

In last year's survey, the professionals also came up with 50 different answers but the gap between the highest and lowest was about 50 percent; this year, the highest was almost 300 percent of the lowest.

"I was completely surprised by the results," said Wesley R. Fitzpatrick of the Portland, Ore., office of Grant Thornton accountants, who made up this year's test.

"When the tax-reform law was new, you could understand the confusion, but now it's hard to explain all the mistakes about fundamental rules," Fitzpatrick said.

The hypothetical family's tax return was tackled by 30 independent certified public accountants, 12 representatives of franchise return-preparation outlets, three CPAs from national accounting companies and five enrolled agents, who are tested and licensed by the Internal Revenue Service. Their fees range from $325 to $2,500.

According to Money, the only preparers who made no major goofs were five independent CPAs, one enrolled agent, four franchised preparers and Fitzpatrick, who devised the test.

For the test, Fitzpatrick conjured up a three-member family whose tax problems are unlikely to be faced by most taxpayers. However, Money said, the experts made mistakes on basic tax provisions that could affect taxpayers at almost any income level.