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Finding the Fourth Proportional to 706.40, 974.79 and 391.65

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Solution

The fourth proportional to 706.40, 974.79 and 391.65 is: 540.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    706.40 : 974.79 = 391.65 : x
  2. Step 2: Convert to fraction form
    706.40/974.79 = 391.65/x
  3. Step 3: Cross multiply
    706.40x = 974.79 × 391.65
  4. Step 4: Simplify right side
    706.40x = 381,776.50
  5. Step 5: Solve for x
    x = 381,776.50/706.40
  6. Step 6: Final answer
    x = 540.45

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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.