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<table width="100%" summary="page for Wan.std"><tr><td>Wan.std</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Wan et al.'s standard deviation estimators</h2>

<h3>Description</h3>

<p>Use Wan et al.'s methods (Wan et al., 2014) to estimate the sample standard deviation based on sample quantiles derived summaries for a single study.
</p>


<h3>Usage</h3>

<pre>
Wan.std(X, n, type)
</pre>


<h3>Arguments</h3>

<table summary="R argblock">
<tr valign="top"><td><code>X</code></td>
<td>
<p>a vector of ordered summary statistics</p>
</td></tr>
<tr valign="top"><td><code>n</code></td>
<td>
<p>the sample size</p>
</td></tr>
<tr valign="top"><td><code>type</code></td>
<td>
<p>a character string indicating which type of summary statistics is reported. The options for the <strong>type</strong> argument are: 
</p>

<ul>
<li><p> &quot;S1&quot; for the sample mean, minimum and maximum values
</p>
</li>
<li><p> &quot;S2&quot; for the sample mean, first and third quartiles
</p>
</li>
<li><p> &quot;S3&quot; for the sample mean, first and third quartiles, and minimum and maximum values
</p>
</li></ul>
</td></tr>
</table>


<h3>References</h3>

<p>Wan X,Wang W, Liu J, and Tong T. (2014). Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range. <em>BMC Medical Research Methodology</em>, <strong>14</strong>:135.
</p>


<h3>Examples</h3>

<pre>
X&lt;-c(1,4,10)
n&lt;-30
type&lt;-"S1"
Wan.std(X,n,type)
</pre>


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