I have installed Android Studio on my MacBook Air (OS Version 10.11 El Capitan) and have successfully written a small \"hello, world\" app and installed on device (Nexus 7)
The default path of Android SDK is /Users/<username>/Library/Android/sdk
, you can refer to this post.
add this to your .bash_profile to add the environment variable
export PATH="/Users/<username>/Library/Android/sdk/tools:/Users/<username>/Library/Android/sdk/build-tools:${PATH}"
Then save the file.
load it
source ./.bash_profile