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Finding the Fourth Proportional to 670.56, 925.29 and 390.85

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Solution

The fourth proportional to 670.56, 925.29 and 390.85 is: 539.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.56 : 925.29 = 390.85 : x
  2. Step 2: Convert to fraction form
    670.56/925.29 = 390.85/x
  3. Step 3: Cross multiply
    670.56x = 925.29 × 390.85
  4. Step 4: Simplify right side
    670.56x = 361,649.60
  5. Step 5: Solve for x
    x = 361,649.60/670.56
  6. Step 6: Final answer
    x = 539.32

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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.