Home / 1,428.02-2,140.20-648

Finding the Fourth Proportional to 1,428.02, 2,140.20 and 648

Calculator

Solution

The fourth proportional to 1,428.02, 2,140.20 and 648 is: 971.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,428.02 : 2,140.20 = 648 : x
  2. Step 2: Convert to fraction form
    1,428.02/2,140.20 = 648/x
  3. Step 3: Cross multiply
    1,428.02x = 2,140.20 × 648
  4. Step 4: Simplify right side
    1,428.02x = 1,386,849.60
  5. Step 5: Solve for x
    x = 1,386,849.60/1,428.02
  6. Step 6: Final answer
    x = 971.17

Related Problems

Find fourth proportional to 714.01, 1,070.10 and 324
Half scale
Find fourth proportional to 2,856.04, 4,280.40 and 1,296
Double scale
Find fourth proportional to 1,429.02, 2,141.70 and 649
Similar ratio
Find fourth proportional to 2,142.03, 3,210.30 and 972
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.