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Finding the Fourth Proportional to 708.40, 977.43 and 428.55

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Solution

The fourth proportional to 708.40, 977.43 and 428.55 is: 591.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.40 : 977.43 = 428.55 : x
  2. Step 2: Convert to fraction form
    708.40/977.43 = 428.55/x
  3. Step 3: Cross multiply
    708.40x = 977.43 × 428.55
  4. Step 4: Simplify right side
    708.40x = 418,877.63
  5. Step 5: Solve for x
    x = 418,877.63/708.40
  6. Step 6: Final answer
    x = 591.30

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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.