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Finding the Fourth Proportional to 419.80, 628.08 and 418.72

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Solution

The fourth proportional to 419.80, 628.08 and 418.72 is: 626.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.80 : 628.08 = 418.72 : x
  2. Step 2: Convert to fraction form
    419.80/628.08 = 418.72/x
  3. Step 3: Cross multiply
    419.80x = 628.08 × 418.72
  4. Step 4: Simplify right side
    419.80x = 262,989.66
  5. Step 5: Solve for x
    x = 262,989.66/419.80
  6. Step 6: Final answer
    x = 626.46

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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.