The following statements all contain errors. Identify and explain the error(s) in each case:
a) There is a moderately weak correlation of r = 0.3 between men's and women's wages in New Zealand.
b) The correlation between Nick Willis' times for the 1500m and 3000m is a strong r = 1.21
c) There is an extremely weak correlation of r = -0.94 between the duration of dementia with the degree of cognitive functioning.