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Finding the Fourth Proportional to 690.70, 952.68 and 428.80

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Solution

The fourth proportional to 690.70, 952.68 and 428.80 is: 591.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.70 : 952.68 = 428.80 : x
  2. Step 2: Convert to fraction form
    690.70/952.68 = 428.80/x
  3. Step 3: Cross multiply
    690.70x = 952.68 × 428.80
  4. Step 4: Simplify right side
    690.70x = 408,509.18
  5. Step 5: Solve for x
    x = 408,509.18/690.70
  6. Step 6: Final answer
    x = 591.44

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.