diff --git a/extensions-core/stats/src/main/java/org/apache/druid/query/aggregation/variance/sql/BaseVarianceSqlAggregator.java b/extensions-core/stats/src/main/java/org/apache/druid/query/aggregation/variance/sql/BaseVarianceSqlAggregator.java
index 0b1562eb83d1..ee8c469c3b86 100644
--- a/extensions-core/stats/src/main/java/org/apache/druid/query/aggregation/variance/sql/BaseVarianceSqlAggregator.java
+++ b/extensions-core/stats/src/main/java/org/apache/druid/query/aggregation/variance/sql/BaseVarianceSqlAggregator.java
@@ -30,6 +30,7 @@
 import org.apache.calcite.sql.SqlKind;
 import org.apache.calcite.sql.type.OperandTypes;
 import org.apache.calcite.sql.type.ReturnTypes;
+import org.apache.calcite.sql.type.SqlTypeName;
 import org.apache.druid.java.util.common.IAE;
 import org.apache.druid.java.util.common.StringUtils;
 import org.apache.druid.query.aggregation.AggregatorFactory;
@@ -60,17 +61,17 @@ public abstract class BaseVarianceSqlAggregator implements SqlAggregator
   private static final String STDDEV_NAME = "STDDEV";
 
   private static final SqlAggFunction VARIANCE_SQL_AGG_FUNC_INSTANCE =
-      buildSqlAvgAggFunction(VARIANCE_NAME);
+      buildSqlVarianceAggFunction(VARIANCE_NAME);
   private static final SqlAggFunction VARIANCE_POP_SQL_AGG_FUNC_INSTANCE =
-      buildSqlAvgAggFunction(SqlKind.VAR_POP.name());
+      buildSqlVarianceAggFunction(SqlKind.VAR_POP.name());
   private static final SqlAggFunction VARIANCE_SAMP_SQL_AGG_FUNC_INSTANCE =
-      buildSqlAvgAggFunction(SqlKind.VAR_SAMP.name());
+      buildSqlVarianceAggFunction(SqlKind.VAR_SAMP.name());
   private static final SqlAggFunction STDDEV_SQL_AGG_FUNC_INSTANCE =
-      buildSqlAvgAggFunction(STDDEV_NAME);
+      buildSqlVarianceAggFunction(STDDEV_NAME);
   private static final SqlAggFunction STDDEV_POP_SQL_AGG_FUNC_INSTANCE =
-      buildSqlAvgAggFunction(SqlKind.STDDEV_POP.name());
+      buildSqlVarianceAggFunction(SqlKind.STDDEV_POP.name());
   private static final SqlAggFunction STDDEV_SAMP_SQL_AGG_FUNC_INSTANCE =
-      buildSqlAvgAggFunction(SqlKind.STDDEV_SAMP.name());
+      buildSqlVarianceAggFunction(SqlKind.STDDEV_SAMP.name());
 
   @Nullable
   @Override
@@ -160,14 +161,15 @@ public Aggregation toDruidAggregation(
   }
 
   /**
-   * Creates a {@link SqlAggFunction} that is the same as {@link org.apache.calcite.sql.fun.SqlAvgAggFunction}
-   * but with an operand type that accepts variance aggregator objects in addition to numeric inputs.
+   * Creates a {@link SqlAggFunction}
+   *
+   * It accepts variance aggregator objects in addition to numeric inputs.
    */
-  private static SqlAggFunction buildSqlAvgAggFunction(String name)
+  private static SqlAggFunction buildSqlVarianceAggFunction(String name)
   {
     return OperatorConversions
         .aggregatorBuilder(name)
-        .returnTypeInference(ReturnTypes.AVG_AGG_FUNCTION)
+        .returnTypeInference(ReturnTypes.explicit(SqlTypeName.DOUBLE))
         .operandTypeChecker(
             OperandTypes.or(
                 OperandTypes.NUMERIC,
diff --git a/extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/sql/VarianceSqlAggregatorTest.java b/extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/sql/VarianceSqlAggregatorTest.java
index fe68b2737ef3..e45a93784967 100644
--- a/extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/sql/VarianceSqlAggregatorTest.java
+++ b/extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/sql/VarianceSqlAggregatorTest.java
@@ -171,8 +171,8 @@ public void testVarPop()
     final List<Object[]> expectedResults = ImmutableList.of(
         new Object[]{
             holder1.getVariance(true),
-            holder2.getVariance(true).doubleValue(),
-            holder3.getVariance(true).longValue()
+            holder2.getVariance(true),
+            holder3.getVariance(true)
         }
     );
     testQuery(
@@ -219,7 +219,7 @@ public void testVarSamp()
         new Object[] {
             holder1.getVariance(false),
             holder2.getVariance(false).doubleValue(),
-            holder3.getVariance(false).longValue(),
+            holder3.getVariance(false),
         }
     );
     testQuery(
@@ -266,7 +266,7 @@ public void testStdDevPop()
         new Object[] {
             Math.sqrt(holder1.getVariance(true)),
             Math.sqrt(holder2.getVariance(true)),
-            (long) Math.sqrt(holder3.getVariance(true)),
+            Math.sqrt(holder3.getVariance(true)),
         }
     );
 
@@ -321,7 +321,7 @@ public void testStdDevSamp()
         new Object[]{
             Math.sqrt(holder1.getVariance(false)),
             Math.sqrt(holder2.getVariance(false)),
-            (long) Math.sqrt(holder3.getVariance(false)),
+            Math.sqrt(holder3.getVariance(false)),
         }
     );
 
@@ -374,7 +374,7 @@ public void testStdDevWithVirtualColumns()
         new Object[]{
             Math.sqrt(holder1.getVariance(false)),
             Math.sqrt(holder2.getVariance(false)),
-            (long) Math.sqrt(holder3.getVariance(false)),
+            Math.sqrt(holder3.getVariance(false)),
         }
     );
 
@@ -543,7 +543,7 @@ public void testEmptyTimeseriesResults()
         ),
         ImmutableList.of(
             NullHandling.replaceWithDefault()
-            ? new Object[]{0.0, 0.0, 0.0, 0.0, 0L, 0L, 0L, 0L}
+            ? new Object[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0}
             : new Object[]{null, null, null, null, null, null, null, null}
         )
     );
@@ -623,7 +623,7 @@ public void testGroupByAggregatorDefaultValues()
         ),
         ImmutableList.of(
             NullHandling.replaceWithDefault()
-            ? new Object[]{"a", 0.0, 0.0, 0.0, 0.0, 0L, 0L, 0L, 0L}
+            ? new Object[]{"a", 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0}
             : new Object[]{"a", null, null, null, null, null, null, null, null}
         )
     );
@@ -688,9 +688,9 @@ public void assertResultsEquals(String sql, List<Object[]> expectedResults, List
       Assert.assertEquals(expectedResult.length, result.length);
       for (int j = 0; j < expectedResult.length; j++) {
         if (expectedResult[j] instanceof Float) {
-          Assert.assertEquals((Float) expectedResult[j], (Float) result[j], 1e-10);
+          Assert.assertEquals((Float) expectedResult[j], (Float) result[j], 1e-5);
         } else if (expectedResult[j] instanceof Double) {
-          Assert.assertEquals((Double) expectedResult[j], (Double) result[j], 1e-10);
+          Assert.assertEquals((Double) expectedResult[j], (Double) result[j], 1e-5);
         } else {
           Assert.assertEquals(expectedResult[j], result[j]);
         }