Four in 10 adults attended church or synagogue in a typical week of 1978.

The rate of attendance for 1977, 41 percent, was virtually the same. Little change has occurred in recent years, although the trend reveals an overall gradual decline in attendance since 1955 when church attendance hit a record peak. That year 49 percent attended in a typical week.

The latest findings emerge from annual Gallup audits of church attendance. To estimate the average attendance during 1978, surveys of representative samples of the adult population were made in five selected weeks during the year.A total of more than 7,500 adults, 18 and older, were interviewed in person at more than 300 scientifically selected sampling locations. This question was asked: "Did you yourself happed to attend church or synagogue in the last seven days?"

Since 1955, when the annual Gallup audits of church attendance were started, the weekly averages have declined from about 50 percent to about 40 percent. High points were recorded in 1955 and again in 1958, when 49 percent attended in an average week.

Analysis of the 1978 figures shows attendance higher among Catholics than Protestants, and higher among women than men. Adults 18 to 29 years old were less likely to attend than those 30 and over.