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Finding the Fourth Proportional to 775.45, 1,069.70 and 491.35

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Solution

The fourth proportional to 775.45, 1,069.70 and 491.35 is: 677.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.45 : 1,069.70 = 491.35 : x
  2. Step 2: Convert to fraction form
    775.45/1,069.70 = 491.35/x
  3. Step 3: Cross multiply
    775.45x = 1,069.70 × 491.35
  4. Step 4: Simplify right side
    775.45x = 525,593.19
  5. Step 5: Solve for x
    x = 525,593.19/775.45
  6. Step 6: Final answer
    x = 677.79

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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.