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Finding the Fourth Proportional to 670.80, 925.81 and 391.13

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Solution

The fourth proportional to 670.80, 925.81 and 391.13 is: 539.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.80 : 925.81 = 391.13 : x
  2. Step 2: Convert to fraction form
    670.80/925.81 = 391.13/x
  3. Step 3: Cross multiply
    670.80x = 925.81 × 391.13
  4. Step 4: Simplify right side
    670.80x = 362,106.46
  5. Step 5: Solve for x
    x = 362,106.46/670.80
  6. Step 6: Final answer
    x = 539.81

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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.