title: fable from distribution to confidence interval
body: <p>I manage to use fable for the forecast then get the result
  <a href="https://i.stack.imgur.com/fau9m.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fau9m.png" alt="enter image description here"></a> </p>
  
  <p>could I have some guidance on how to change this distribution to 80% 95% confidence interval? thank you!</p>
  
  <p>you can use the sample code here to get the distribution</p>
  
  <pre><code>result &lt;–USAccDeaths %&gt;% as_tsibble %&gt;% 
    model(arima = ARIMA(log(value) ~ pdq(0,1,1) + PDQ(0,1,1)))%&gt;%
    forecast(h=12)
  </code></pre>