diff --git a/2_37.sch b/2_37.sch
new file mode 100644
index 0000000..61024c3
--- /dev/null
+++ b/2_37.sch
@@ -0,0 +1,28 @@
+(define (accumulate op initial sequence)
+  (if (null? sequence)
+      initial
+      (op (car sequence)
+          (accumulate op initial (cdr sequence)))))
+
+(define (accumulate-n op init seqs)
+  (if (null? (car seqs))
+      '()
+      (cons (accumulate op init (map car seqs))
+	    (accumulate-n op init (map cdr seqs)))))
+
+(define (dot-product v w)
+  (accumulate + 0 (map * v w)))
+
+(define (matrix-*-vector m v)
+  (map (lambda (row) (dot-product row v)) m))
+
+(define (transpose m)
+  (accumulate-n cons '() m))
+
+(define (matrix-*-matrix m n)
+  (let ((cols (transpose n)))
+    (map (lambda (row) 
+	 	 (map (lambda (col) 
+			      (dot-product row col)) 
+		      cols))
+	 m)))