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Finding the Fourth Proportional to 479.76, 716.39 and 420.75

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Solution

The fourth proportional to 479.76, 716.39 and 420.75 is: 628.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.76 : 716.39 = 420.75 : x
  2. Step 2: Convert to fraction form
    479.76/716.39 = 420.75/x
  3. Step 3: Cross multiply
    479.76x = 716.39 × 420.75
  4. Step 4: Simplify right side
    479.76x = 301,421.83
  5. Step 5: Solve for x
    x = 301,421.83/479.76
  6. Step 6: Final answer
    x = 628.28

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.