Home / 1,280.40-1,921.08-458.64

Finding the Fourth Proportional to 1,280.40, 1,921.08 and 458.64

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Solution

The fourth proportional to 1,280.40, 1,921.08 and 458.64 is: 688.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.40 : 1,921.08 = 458.64 : x
  2. Step 2: Convert to fraction form
    1,280.40/1,921.08 = 458.64/x
  3. Step 3: Cross multiply
    1,280.40x = 1,921.08 × 458.64
  4. Step 4: Simplify right side
    1,280.40x = 881,084.13
  5. Step 5: Solve for x
    x = 881,084.13/1,280.40
  6. Step 6: Final answer
    x = 688.13

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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.