A liquid fills a horizontal capillary tube whose one end is dipped in a large pool of the liquid. Experiments show that the distance L travelled by the liquid meniscus inside the capillary in time t is given by
L = kyaRbµ√t,
where γ is the surface tension, R is the inner radius of the capillary, and µ is the dynamic viscosity of the liquid. If k is a dimensionless constant, then the exponent α is ___ (rounded off to 1 decimal place).