title: Need help using Excel data in R
body: <p>I'm just starting to use R and imported an Excel file named tblMainXmasFund.xlsx. I can read it using</p>
  <pre class="lang-r prettyprint-override"><code>readxl::read_excel(&quot;C:/Excel/For R/tblMainXmasFund.xlsx&quot;). 
  </code></pre>
  <p>However, when I try to do calculations like <code>sum(Amount)</code> I get:</p>
  <blockquote>
  <p>Error: object 'Amount' not found.
  If I use <code>sum(&quot;Amount&quot;)</code> I get:
  invalid 'type' (character) of argument.</p>
  </blockquote>
  <p>R recognizes the Amount column as being numeric (it's actually double) so I'm guessing I need to change my syntax but don't know to what.</p>
  <p>There are only two columns of data (CheckDate and Amount) I will be using so would like to know the code for doing a calculation like <code>sum(Amount)</code> where <code>CheckDate &gt;=10/1/2022</code> and <code>&lt;=12/31/2022</code>. All suggestions are appreciated.</p>