fix: incorrect valuation rate in stock reconciliation
diff --git a/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.py b/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.py
index e646600..dd94e7c 100644
--- a/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.py
+++ b/erpnext/stock/doctype/stock_reconciliation/stock_reconciliation.py
@@ -404,17 +404,18 @@
 
 			key = (d.item_code, d.warehouse)
 			if key not in merge_similar_entries:
+				d.total_amount = (d.actual_qty * d.valuation_rate)
 				merge_similar_entries[key] = d
 			elif d.serial_no:
 				data = merge_similar_entries[key]
 				data.actual_qty += d.actual_qty
 				data.qty_after_transaction += d.qty_after_transaction
 
-				data.valuation_rate = (data.valuation_rate + d.valuation_rate) / data.actual_qty
+				data.total_amount += (d.actual_qty * d.valuation_rate)
+				data.valuation_rate = (data.total_amount) / data.actual_qty
 				data.serial_no += '\n' + d.serial_no
 
-				if data.incoming_rate:
-					data.incoming_rate = (data.incoming_rate + d.incoming_rate) / data.actual_qty
+				data.incoming_rate = (data.total_amount) / data.actual_qty
 
 		for key, value in merge_similar_entries.items():
 			new_sl_entries.append(value)
diff --git a/erpnext/stock/doctype/stock_reconciliation/test_stock_reconciliation.py b/erpnext/stock/doctype/stock_reconciliation/test_stock_reconciliation.py
index 36380b8..ce4cbd2 100644
--- a/erpnext/stock/doctype/stock_reconciliation/test_stock_reconciliation.py
+++ b/erpnext/stock/doctype/stock_reconciliation/test_stock_reconciliation.py
@@ -6,7 +6,7 @@
 
 from __future__ import unicode_literals
 import frappe, unittest
-from frappe.utils import flt, nowdate, nowtime
+from frappe.utils import flt, nowdate, nowtime, random_string
 from erpnext.accounts.utils import get_stock_and_account_balance
 from erpnext.stock.stock_ledger import get_previous_sle, update_entries_after
 from erpnext.stock.doctype.stock_reconciliation.stock_reconciliation import EmptyStockReconciliationItemsError, get_items
@@ -150,6 +150,42 @@
 			stock_doc = frappe.get_doc("Stock Reconciliation", d)
 			stock_doc.cancel()
 
+
+	def test_stock_reco_for_merge_serialized_item(self):
+		to_delete_records = []
+
+		# Add new serial nos
+		serial_item_code = "Stock-Reco-Serial-Item-2"
+		serial_warehouse = "_Test Warehouse for Stock Reco1 - _TC"
+
+		sr = create_stock_reconciliation(item_code=serial_item_code, serial_no=random_string(6),
+			warehouse = serial_warehouse, qty=1, rate=100, do_not_submit=True, purpose='Opening Stock')
+
+		for i in range(3):
+			sr.append('items', {
+				'item_code': serial_item_code,
+				'warehouse': serial_warehouse,
+				'qty': 1,
+				'valuation_rate': 100,
+				'serial_no': random_string(6)
+			})
+
+		sr.save()
+		sr.submit()
+
+		sle_entries = frappe.get_all('Stock Ledger Entry', filters= {'voucher_no': sr.name},
+			fields = ['name', 'incoming_rate'])
+
+		self.assertEqual(len(sle_entries), 1)
+		self.assertEqual(sle_entries[0].incoming_rate, 100)
+
+		to_delete_records.append(sr.name)
+		to_delete_records.reverse()
+
+		for d in to_delete_records:
+			stock_doc = frappe.get_doc("Stock Reconciliation", d)
+			stock_doc.cancel()
+
 	def test_stock_reco_for_batch_item(self):
 		to_delete_records = []
 		to_delete_serial_nos = []
@@ -231,6 +267,12 @@
 		serial_item_doc.serial_no_series = "SRSI.####"
 		serial_item_doc.save(ignore_permissions=True)
 
+	serial_item_doc = create_item("Stock-Reco-Serial-Item-2", is_stock_item=1)
+	if not serial_item_doc.has_serial_no:
+		serial_item_doc.has_serial_no = 1
+		serial_item_doc.serial_no_series = "SRSII.####"
+		serial_item_doc.save(ignore_permissions=True)
+
 	batch_item_doc = create_item("Stock-Reco-batch-Item-1", is_stock_item=1)
 	if not batch_item_doc.has_batch_no:
 		batch_item_doc.has_batch_no = 1