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Finding the Fourth Proportional to 1,005.84, 1,507.68 and 428.16

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Solution

The fourth proportional to 1,005.84, 1,507.68 and 428.16 is: 641.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,005.84 : 1,507.68 = 428.16 : x
  2. Step 2: Convert to fraction form
    1,005.84/1,507.68 = 428.16/x
  3. Step 3: Cross multiply
    1,005.84x = 1,507.68 × 428.16
  4. Step 4: Simplify right side
    1,005.84x = 645,528.27
  5. Step 5: Solve for x
    x = 645,528.27/1,005.84
  6. Step 6: Final answer
    x = 641.78

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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.