Decrease visibility.
diff --git a/src/main/java/org/apache/commons/math4/stat/descriptive/rank/Percentile.java b/src/main/java/org/apache/commons/math4/stat/descriptive/rank/Percentile.java
index 9bd7e62..ca71269 100644
--- a/src/main/java/org/apache/commons/math4/stat/descriptive/rank/Percentile.java
+++ b/src/main/java/org/apache/commons/math4/stat/descriptive/rank/Percentile.java
@@ -564,7 +564,7 @@
* @return work array sliced from values in the range [begin,begin+length)
* @throws MathIllegalArgumentException if values or indices are invalid
*/
- protected double[] getWorkArray(final double[] values, final int begin, final int length) {
+ private double[] getWorkArray(final double[] values, final int begin, final int length) {
final double[] work;
if (values == getDataRef()) {
work = getDataRef();