If a, b, c, d are in proportion, then a/b = c/d. Here, 4/9 = 12/d. So, d = (9 * 12) / 4 = 108 / 4 = 27.
यदि a, b, c, d समानुपात में हैं, तो a/b = c/d। यहाँ, 4/9 = 12/d। इसलिए, d = (9 * 12) / 4 = 108 / 4 = 27।