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Finding the Fourth Proportional to 438.80, 605.07 and 428.78

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Solution

The fourth proportional to 438.80, 605.07 and 428.78 is: 591.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.80 : 605.07 = 428.78 : x
  2. Step 2: Convert to fraction form
    438.80/605.07 = 428.78/x
  3. Step 3: Cross multiply
    438.80x = 605.07 × 428.78
  4. Step 4: Simplify right side
    438.80x = 259,441.91
  5. Step 5: Solve for x
    x = 259,441.91/438.80
  6. Step 6: Final answer
    x = 591.25

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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.