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Finding the Fourth Proportional to 781.71, 1,077.98 and 663.55

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Solution

The fourth proportional to 781.71, 1,077.98 and 663.55 is: 915.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.71 : 1,077.98 = 663.55 : x
  2. Step 2: Convert to fraction form
    781.71/1,077.98 = 663.55/x
  3. Step 3: Cross multiply
    781.71x = 1,077.98 × 663.55
  4. Step 4: Simplify right side
    781.71x = 715,293.63
  5. Step 5: Solve for x
    x = 715,293.63/781.71
  6. Step 6: Final answer
    x = 915.04

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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.