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Finding the Fourth Proportional to 781.34, 1,177.88 and 728.48

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Solution

The fourth proportional to 781.34, 1,177.88 and 728.48 is: 1,098.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.34 : 1,177.88 = 728.48 : x
  2. Step 2: Convert to fraction form
    781.34/1,177.88 = 728.48/x
  3. Step 3: Cross multiply
    781.34x = 1,177.88 × 728.48
  4. Step 4: Simplify right side
    781.34x = 858,061.32
  5. Step 5: Solve for x
    x = 858,061.32/781.34
  6. Step 6: Final answer
    x = 1,098.20

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.