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Finding the Fourth Proportional to 781.40, 1,173.51 and 677.85

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Solution

The fourth proportional to 781.40, 1,173.51 and 677.85 is: 1,018.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.40 : 1,173.51 = 677.85 : x
  2. Step 2: Convert to fraction form
    781.40/1,173.51 = 677.85/x
  3. Step 3: Cross multiply
    781.40x = 1,173.51 × 677.85
  4. Step 4: Simplify right side
    781.40x = 795,463.75
  5. Step 5: Solve for x
    x = 795,463.75/781.40
  6. Step 6: Final answer
    x = 1,018.00

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.