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Finding the Fourth Proportional to 781.19, 1,076.81 and 615.14

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Solution

The fourth proportional to 781.19, 1,076.81 and 615.14 is: 847.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.19 : 1,076.81 = 615.14 : x
  2. Step 2: Convert to fraction form
    781.19/1,076.81 = 615.14/x
  3. Step 3: Cross multiply
    781.19x = 1,076.81 × 615.14
  4. Step 4: Simplify right side
    781.19x = 662,388.52
  5. Step 5: Solve for x
    x = 662,388.52/781.19
  6. Step 6: Final answer
    x = 847.92

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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.