PL HELP Why was the Yellow River important for ancient Chinese dynasties? Without the protection provided by the river, dynasties were open to invasion.

Without the food grown in the river valley, dynasties could not remain in power.

Without the transportation provided by the river, dynasties could not reach the sea.

Without the large population in the river valley, dynasties were unable to raise armies.

Match the item to the definition: indirect correlation, correlational research, correlational research, covary, pearson correlation coefficient, pearson correlation coefficient, direct correlation a. used to describe the relationship between two or more naturally occurring variables b. determines whether scores on the two variables covary c. whether two variables vary or change together d. denoted by the symbol "r" e. provides information about the sign (direction) and magnitude(strength) of the linear relationship. f. when the correlation is positiveg. when the correlation is negative