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Finding the Fourth Proportional to 839.66, 1,159.95 and 663.78

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Solution

The fourth proportional to 839.66, 1,159.95 and 663.78 is: 916.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.66 : 1,159.95 = 663.78 : x
  2. Step 2: Convert to fraction form
    839.66/1,159.95 = 663.78/x
  3. Step 3: Cross multiply
    839.66x = 1,159.95 × 663.78
  4. Step 4: Simplify right side
    839.66x = 769,958.45
  5. Step 5: Solve for x
    x = 769,958.45/839.66
  6. Step 6: Final answer
    x = 916.99

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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.