  Frequencies of intermediate-degree f-modes of the Sun seem to indicate that
the solar radius is smaller than what is normally used in constructing solar
models. We investigate the possible consequences of an error in radius on
results for solar structure obtained using helioseismic inversions. It is shown
that solar sound speed will be overestimated if oscillation frequencies are
inverted using reference models with a larger radius. Using solar models with
radius of 695.78 Mm and new data sets, the base of the solar convection zone is
estimated to be at radial distance of $0.7135\pm 0.0005$ of the solar radius.
The helium abundance in the convection zone as determined using models with
OPAL equation of state is $0.248\pm 0.001$, where the errors reflect the
estimated systematic errors in the calculation, the statistical errors being
much smaller. Assuming that the OPAL opacities used in the construction of the
solar models are correct, the surface $Z/X$ is estimated to be $0.0245\pm
0.0006$.
