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Finding the Fourth Proportional to 1,002.60, 1,381.93 and 781.17

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Solution

The fourth proportional to 1,002.60, 1,381.93 and 781.17 is: 1,076.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,002.60 : 1,381.93 = 781.17 : x
  2. Step 2: Convert to fraction form
    1,002.60/1,381.93 = 781.17/x
  3. Step 3: Cross multiply
    1,002.60x = 1,381.93 × 781.17
  4. Step 4: Simplify right side
    1,002.60x = 1,079,522.26
  5. Step 5: Solve for x
    x = 1,079,522.26/1,002.60
  6. Step 6: Final answer
    x = 1,076.72

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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.