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Finding the Fourth Proportional to 655.18, 980.30 and 390.66

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Solution

The fourth proportional to 655.18, 980.30 and 390.66 is: 584.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    655.18 : 980.30 = 390.66 : x
  2. Step 2: Convert to fraction form
    655.18/980.30 = 390.66/x
  3. Step 3: Cross multiply
    655.18x = 980.30 × 390.66
  4. Step 4: Simplify right side
    655.18x = 382,962.52
  5. Step 5: Solve for x
    x = 382,962.52/655.18
  6. Step 6: Final answer
    x = 584.51

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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.