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Finding the Fourth Proportional to 840.01, 1,257.68 and 428.26

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Solution

The fourth proportional to 840.01, 1,257.68 and 428.26 is: 641.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.01 : 1,257.68 = 428.26 : x
  2. Step 2: Convert to fraction form
    840.01/1,257.68 = 428.26/x
  3. Step 3: Cross multiply
    840.01x = 1,257.68 × 428.26
  4. Step 4: Simplify right side
    840.01x = 538,614.04
  5. Step 5: Solve for x
    x = 538,614.04/840.01
  6. Step 6: Final answer
    x = 641.20

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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.