Home / 1,420.77-2,128.08-688.81

Finding the Fourth Proportional to 1,420.77, 2,128.08 and 688.81

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Solution

The fourth proportional to 1,420.77, 2,128.08 and 688.81 is: 1,031.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.77 : 2,128.08 = 688.81 : x
  2. Step 2: Convert to fraction form
    1,420.77/2,128.08 = 688.81/x
  3. Step 3: Cross multiply
    1,420.77x = 2,128.08 × 688.81
  4. Step 4: Simplify right side
    1,420.77x = 1,465,842.78
  5. Step 5: Solve for x
    x = 1,465,842.78/1,420.77
  6. Step 6: Final answer
    x = 1,031.72

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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.