td adding extra margin or padding to right of element - html

Question

On an assignment for my teacher, we are making a table in which I want each td element to be 200px wide for a total of 5 cells which equal to 1000px (wrapper). When I do this however, the last td in each tr jumps down to the next line when they should all line up properly with no issues.
EDIT: Solved! (Read comments)
Here is my code for the table:
<table id="assignment-table">
<tr>
<th>Assignment</th>
<th>Fall 2013</th>
<th>Responsive?</th>
<th>Winter 2014</th>
<th>Responsive?</th>
</tr>
<tr>
<td>A1</td>
<td>Code Provided Site</td>
<td>No</td>
<td>Designasaurus</td>
<td>Yes</td>
</tr>
<tr>
<td>A2a</td>
<td>Restaurant Mock-up</td>
<td>N/a</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td>A2b</td>
<td>Restaurant Static</td>
<td>No</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td>A3a</td>
<td>Adaptive Excercise</td>
<td>No</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td>A3b</td>
<td>Responsive Excercise</td>
<td>Yes</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td>A4</td>
<td>Restaurant Final</td>
<td>Yes</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td>A5a</td>
<td>Final Mock-up</td>
<td>N/a</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td>A5b</td>
<td>Final Site</td>
<td>Yes</td>
<td>TBA</td>
<td>-</td>
</tr>
<tr>
<td class="lastrow">NSCC GRAPHIC DESIGN | 2012-14</td>
</tr>
</table>
</div>
And then the CSS:
#content {
width: 100%;
color: white;
}
#assignment-table {
font-size: 16px;
border-spacing: 0!important;
border-collapse: collapse;
}
#assignment-table th {
display: inline-block;
padding: 25px 0;
width: 200px;
text-align: center;
}
#assignment-table tr {
display: block;
border-bottom: 1px solid #ffffff;
}
#assignment-table tr:last-child {
width: 1000px;
border-bottom: none!important;
}
#assignment-table td {
display: inline-block;
padding: 25px 0;
width: 200px;
text-align: center;
}
.lastrow {
width: 1000px!important;
}
th:nth-child(3) {
background-color: rgba(255,255,255,0.05);
}
td:nth-child(3) {
background-color: rgba(255,255,255,0.05);
font-family: 'source_sans_proitalic';
}
th:nth-child(5) {
background-color: rgba(255,255,255,0.05);
}
td:nth-child(5) {
background-color: rgba(255,255,255,0.05);
font-family: 'source_sans_proitalic';
}
It should look like this:

Answer 1

It looks like you have display: inline-block; on your table cells. inline-block will automatically insert a space between elements. It's this space that is adding up and wrapping your last element. I would remove the display: inline-block; from your css entries, since this is a table it doesn't need it anyway.
CSS:
#assignment-table th {
//display: inline-block; <- remove this
padding: 25px 0;
width: 200px;
text-align: center;
}
#assignment-table td {
//display: inline-block; <- remove this
padding: 25px 0;
width: 200px;
text-align: center;
}
EXAMPLE FIDDLE

Answer 2

You are removing the default table behavior by using display: inline-block on tds. Just apply width: 1000px to the table and td { width: 20%; }
EDIT: here you go.