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Finding the Fourth Proportional to 688.29, 1,030 and 428.42

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Solution

The fourth proportional to 688.29, 1,030 and 428.42 is: 641.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.29 : 1,030 = 428.42 : x
  2. Step 2: Convert to fraction form
    688.29/1,030 = 428.42/x
  3. Step 3: Cross multiply
    688.29x = 1,030 × 428.42
  4. Step 4: Simplify right side
    688.29x = 441,272.60
  5. Step 5: Solve for x
    x = 441,272.60/688.29
  6. Step 6: Final answer
    x = 641.11

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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.