Add a median line on my scatter chart

[#1]

anyone know how to add a mediam line on my scatter chart below??

I hv tried a lot of way already but it always change all of my scatter chart. Please help me thank~~~

[#2]

Hi,

   You can add median line using reference line option in presentation tab,

    just give your expression for median in Expression field

regards,

   Vivek

[#3]

i try it a lot of time already but nothing happend.....

[SunilChauhan]

load sample we can give a try?

[#5]

This is wat i have done a lot of time. izzit something wrong with my setting??