title: Error while checking balance using web3 api
body: <p>I am setting up an ethereum environment in mac os following this link <a href="https://medium.com/coinmonks/setting-up-ethereum-development-environment-on-macos-22c96a136ac4" rel="nofollow noreferrer">https://medium.com/coinmonks/setting-up-ethereum-development-environment-on-macos-22c96a136ac4</a> .
  while checking the balance of the account by,</p>
  <pre><code>truffle(develop)&gt; web3.fromWei(web3.eth.getBalance('0x0ac4d68c2c34a3f1324439bff3c119f4ef675a72'),'ether').toNumber()
  </code></pre>
  <p>I get the following errors;</p>
  <pre><code>Thrown:
  evalmachine.&lt;anonymous&gt;:0
  
  
  web3.fromWei(web3.eth.getBalance('0x0ac4d68c2c34a3f1324439bff3c119f4ef675a72'),'ether').toNumber()
   ^
  
  
  
  TypeError: web3.fromWei is not a function
  at evalmachine.&lt;anonymous&gt;:0:6
  at sigintHandlersWrap (vm.js:279:15)
  at Script.runInContext (vm.js:134:14)
  at runScript (/Users/jigmewangmo/Documents/MSIT/BlockChain/EthereumWorkspace/node_modules/truffle/build/webpack:/packages/core/lib/console.js:251:1)
  at Console.interpret (/Users/jigmewangmo/Documents/MSIT/BlockChain/EthereumWorkspace/node_modules/truffle/build/webpack:/packages/core/lib/console.js:266:1)
  at bound (domain.js:420:14)
  at REPLServer.runBound [as eval] (domain.js:433:12)
  at REPLServer.onLine (repl.js:700:10)
  at REPLServer.emit (events.js:209:13)
  at REPLServer.EventEmitter.emit (domain.js:476:20)
  </code></pre>
  <p>Any idea why? I looked for resources online but confused as a suggested solution still gives error. Thank you in advance.</p>