function y = getValueFromTable(yName, xName, x)
  [xa, ya] = getTableRow(yName, xName, x, 'first row ') ;
  if xa==x
    y = ya ;
  else
    [xb, yb] = getTableRow(yName, xName, x, 'second row') ;
    y = linearInterpolation(xa, xb, ya, yb, x) ;
  end
end

function [xRow, yRow] = getTableRow(yName, xName, x, rowNameId)
  message = sprintf('Go to table T-9 near %s = %.2f, %s => [%s, %s] = ', xName, x, rowNameId, xName, yName) ;
  values = input(message) ;
  xRow = values(1) ;
  yRow = values(2) ;
end

function y = linearInterpolation(xa, xb, ya, yb, x)
  y = ya + (x-xa)/(xb-xa)*(yb-ya) ;
end