A researcher wants to study the relationship between women's ages and number of births per year for women in the 10 to 55 age range. The relationship would be expected to be

Which of the following makes it harder to vote?

a. vote-by-mail laws b. the Motor Voter Act c. Election Day voter registration laws d. voter ID laws

Which statement describes how the Chinese economy has changed since the 1950s?

a. It has slowly evolved into a free-market system b. It has moved from a command economy to a mixed economy c. It has shifted from a free-market system to a command economy d. It has come under increasingly greater control by the central government