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Finding the Fourth Proportional to 425.76, 639.17 and 287.06

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Solution

The fourth proportional to 425.76, 639.17 and 287.06 is: 430.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.76 : 639.17 = 287.06 : x
  2. Step 2: Convert to fraction form
    425.76/639.17 = 287.06/x
  3. Step 3: Cross multiply
    425.76x = 639.17 × 287.06
  4. Step 4: Simplify right side
    425.76x = 183,475.51
  5. Step 5: Solve for x
    x = 183,475.51/425.76
  6. Step 6: Final answer
    x = 430.94

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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.