diff --git a/src/main/java/org/apache/commons/math/stat/inference/TTestImpl.java b/src/main/java/org/apache/commons/math/stat/inference/TTestImpl.java
index 20a81a187..fa04d4a6c 100644
--- a/src/main/java/org/apache/commons/math/stat/inference/TTestImpl.java
+++ b/src/main/java/org/apache/commons/math/stat/inference/TTestImpl.java
@@ -35,7 +35,9 @@ import org.apache.commons.math.util.FastMath;
  */
 public class TTestImpl implements TTest  {
 
-    /** Distribution used to compute inference statistics. */
+    /** Distribution used to compute inference statistics.
+     * @deprecated in 2.2 (to be removed in 3.0).
+     */
     private TDistribution distribution;
 
     /**
@@ -50,6 +52,7 @@ public class TTestImpl implements TTest  {
      * inference statistics.
      * @param t distribution used to compute inference statistics.
      * @since 1.2
+     * @deprecated in 2.2 (to be removed in 3.0).
      */
     public TTestImpl(TDistribution t) {
         super();
@@ -1015,6 +1018,7 @@ public class TTestImpl implements TTest  {
      * Modify the distribution used to compute inference statistics.
      * @param value the new distribution
      * @since 1.2
+     * @deprecated in 2.2 (to be removed in 3.0).
      */
     public void setDistribution(TDistribution value) {
         distribution = value;
diff --git a/src/main/java/org/apache/commons/math/stat/regression/SimpleRegression.java b/src/main/java/org/apache/commons/math/stat/regression/SimpleRegression.java
index d5f8d5d69..4fde70023 100644
--- a/src/main/java/org/apache/commons/math/stat/regression/SimpleRegression.java
+++ b/src/main/java/org/apache/commons/math/stat/regression/SimpleRegression.java
@@ -101,12 +101,25 @@ public class SimpleRegression implements Serializable {
      * compute inference statistics.
      * @param t the distribution used to compute inference statistics.
      * @since 1.2
+     * @deprecated in 2.2 (to be removed in 3.0). Please use the {@link
+     * #SimpleRegression(int) other constructor} instead.
      */
     public SimpleRegression(TDistribution t) {
         super();
         setDistribution(t);
     }
 
+    /**
+     * Create an empty SimpleRegression.
+     *
+     * @param degrees Number of degrees of freedom of the distribution
+     * used to compute inference statistics.
+     * @since 2.2
+     */
+    public SimpleRegression(int degrees) {
+        setDistribution(new TDistributionImpl(degrees));
+    }
+
     /**
      * Adds the observation (x,y) to the regression data set.
      * <p>
@@ -611,6 +624,7 @@ public class SimpleRegression implements Serializable {
      * Modify the distribution used to compute inference statistics.
      * @param value the new distribution
      * @since 1.2
+     * @deprecated in 2.2 (to be removed in 3.0).
      */
     public void setDistribution(TDistribution value) {
         distribution = value;
diff --git a/src/main/java/org/apache/commons/math/util/FastMath.java b/src/main/java/org/apache/commons/math/util/FastMath.java
index 9c471e636..4f5616b6f 100644
--- a/src/main/java/org/apache/commons/math/util/FastMath.java
+++ b/src/main/java/org/apache/commons/math/util/FastMath.java
@@ -2881,8 +2881,8 @@ public class FastMath {
     }
 
     /** Compute the cubic root of a number.
-     * @param a number on which evaluation is done
-     * @return cubic root of a
+     * @param x number on which evaluation is done
+     * @return cubic root of x
      */
     public static double cbrt(double x) {
       /* Convert input double to bits */