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Finding the Fourth Proportional to 655.79, 978.15 and 617.72

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Solution

The fourth proportional to 655.79, 978.15 and 617.72 is: 921.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    655.79 : 978.15 = 617.72 : x
  2. Step 2: Convert to fraction form
    655.79/978.15 = 617.72/x
  3. Step 3: Cross multiply
    655.79x = 978.15 × 617.72
  4. Step 4: Simplify right side
    655.79x = 604,219.73
  5. Step 5: Solve for x
    x = 604,219.73/655.79
  6. Step 6: Final answer
    x = 921.36

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.