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Finding the Fourth Proportional to 876.39, 1,209.68 and 561.79

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Solution

The fourth proportional to 876.39, 1,209.68 and 561.79 is: 775.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    876.39 : 1,209.68 = 561.79 : x
  2. Step 2: Convert to fraction form
    876.39/1,209.68 = 561.79/x
  3. Step 3: Cross multiply
    876.39x = 1,209.68 × 561.79
  4. Step 4: Simplify right side
    876.39x = 679,583.29
  5. Step 5: Solve for x
    x = 679,583.29/876.39
  6. Step 6: Final answer
    x = 775.43

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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.