Which of the foolowing statements about relational model is not correct?

The statement "Data in the rows of a table are of the same data type" is not correct. In a relational database model, the columns of a table have a defined data type (such as integer, text, date, etc.), but the data type of values in a row can be different for different columns in that row. For example, in a table of employees, a column for the employee's name might have a data type of text, while a column for their hire date might have a data type of date, and a column for their salary might have a data type of integer. The values in each row of the table would then contain a text value for the name, a date value for the hire date, and an integer value for the salary.