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Finding the Fourth Proportional to 788.80, 1,087.92 and 478

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Solution

The fourth proportional to 788.80, 1,087.92 and 478 is: 659.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    788.80 : 1,087.92 = 478 : x
  2. Step 2: Convert to fraction form
    788.80/1,087.92 = 478/x
  3. Step 3: Cross multiply
    788.80x = 1,087.92 × 478
  4. Step 4: Simplify right side
    788.80x = 520,025.76
  5. Step 5: Solve for x
    x = 520,025.76/788.80
  6. Step 6: Final answer
    x = 659.26

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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.