<image>Look at the picture and answer the questions.
(1) The price of 5 bottles is ____ yuan, and the price of 15 bottles is ____ yuan.
(2) From the picture, it can be seen that the number of bottles purchased and the total price are in ____ proportion.
(3) The cost of buying ____ bottles of mineral water is 36 yuan.
(4) Xiao Ming bought 3 times the number of bottles of mineral water as Xiao Tao. The money spent by Xiao Ming is ____ times that of Xiao Tao.