High school dropout rates are declining for blacks and whites but not for people of Hispanic descent, whose dropout rate has remained high for 20 years, the Education Department said today.

The department's fourth annual dropout report to Congress showed that nationally the high school dropout rate for students from 15 through 24 years old declined to 4 percent in 1991 from 6.1 percent in 1980. That means about 348,000 students in grades 10 through 12 left school without graduating in 1991.

Using a slightly different age sampling, the department measured how many people from 16 to 24 years old were not enrolled in school in 1991 and had not completed high school. It calculated the figure at 12.5 percent of that age group, or 3.9 million people, down from 14.1 percent in 1980. That rate reflects the cumulative effects of the annual numbers of dropouts over several years, as distinct from those who dropped out specifically in 1991.

The report by the National Center for Education Statistics measures the dropout rate in three ways. Officials track those who leave high school each year; the proportion of the population who have not completed high school, regardless of when they dropped out; and a single group of students over a period of time.

From 1972 to 1991, the report showed, the dropout rate for 16-through 24-year-old blacks declined to 13.6 percent from 21.3 percent. For whites in that age group, the rate dropped to 8.9 percent from 12.3 percent. The rate is for those who have not completed high school, regardless of when they dropped out.

According to the report, the Hispanic dropout rate was 35.3 percent in 1991 for those 16 through 24. In 1972, that rate was 34.3 percent.

"What we see looking over the past 10 and 20 years is that the nation is making steady progress," said Diane Ravitch, Assistant Education Secretary. "The other very positive sign is the rate for black and white kids has converged when you look at kids by income group." 'Intolerably High' Rates

But she added, "The Hispanic rates continue to be intolerably high."

When the dropout rate is computed for the 16- through 19-year age group for each state, the District of Columbia had the highest rate, 19.1 percent, followed by 14.9 percent in Nevada, 14.3 in Arizona and in California, 14.2 in Florida and 14.1 in Georgia. North Dakota had the lowest dropout rate, 4.3 percent, followed by Minnesota at 6.1 and Wyoming at 6.3 percent. New York's rate was 10.1, New Jersey's 9.3 and Connecticut's 9.2 percent.

Article published on The New York Times, Sept. 17, 1992