Question: For each pair of variables, identify whether the pair is likely to have a positive correlation, a negative correlation, or no correlation. Briefly indicate your reasoning.
a. Verbal skills and age for children under 12 years old.
b. Height of husband and height of wife.
c. Number of dogs and number of fire hydrants for cities in New York State.
d. Average number of bicycles per household and average January temperature for cities in the United States.