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Finding the Fourth Proportional to 685.98, 946.42 and 391.04

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Solution

The fourth proportional to 685.98, 946.42 and 391.04 is: 539.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.98 : 946.42 = 391.04 : x
  2. Step 2: Convert to fraction form
    685.98/946.42 = 391.04/x
  3. Step 3: Cross multiply
    685.98x = 946.42 × 391.04
  4. Step 4: Simplify right side
    685.98x = 370,088.08
  5. Step 5: Solve for x
    x = 370,088.08/685.98
  6. Step 6: Final answer
    x = 539.50

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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.