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Finding the Fourth Proportional to 705.61, 973.69 and 390.85

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Solution

The fourth proportional to 705.61, 973.69 and 390.85 is: 539.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    705.61 : 973.69 = 390.85 : x
  2. Step 2: Convert to fraction form
    705.61/973.69 = 390.85/x
  3. Step 3: Cross multiply
    705.61x = 973.69 × 390.85
  4. Step 4: Simplify right side
    705.61x = 380,566.74
  5. Step 5: Solve for x
    x = 380,566.74/705.61
  6. Step 6: Final answer
    x = 539.34

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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.