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Finding the Fourth Proportional to 419.12, 628.72 and 145.28

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Solution

The fourth proportional to 419.12, 628.72 and 145.28 is: 217.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.12 : 628.72 = 145.28 : x
  2. Step 2: Convert to fraction form
    419.12/628.72 = 145.28/x
  3. Step 3: Cross multiply
    419.12x = 628.72 × 145.28
  4. Step 4: Simplify right side
    419.12x = 91,340.44
  5. Step 5: Solve for x
    x = 91,340.44/419.12
  6. Step 6: Final answer
    x = 217.93

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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.