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Finding the Fourth Proportional to 876.64, 1,209.69 and 561.35

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Solution

The fourth proportional to 876.64, 1,209.69 and 561.35 is: 774.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    876.64 : 1,209.69 = 561.35 : x
  2. Step 2: Convert to fraction form
    876.64/1,209.69 = 561.35/x
  3. Step 3: Cross multiply
    876.64x = 1,209.69 × 561.35
  4. Step 4: Simplify right side
    876.64x = 679,059.48
  5. Step 5: Solve for x
    x = 679,059.48/876.64
  6. Step 6: Final answer
    x = 774.61

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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.