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Finding the Fourth Proportional to 419.30, 628.95 and 145.70

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Solution

The fourth proportional to 419.30, 628.95 and 145.70 is: 218.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.30 : 628.95 = 145.70 : x
  2. Step 2: Convert to fraction form
    419.30/628.95 = 145.70/x
  3. Step 3: Cross multiply
    419.30x = 628.95 × 145.70
  4. Step 4: Simplify right side
    419.30x = 91,634.87
  5. Step 5: Solve for x
    x = 91,634.87/419.30
  6. Step 6: Final answer
    x = 218.55

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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.