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Finding the Fourth Proportional to 421.02, 628.58 and 396.45

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Solution

The fourth proportional to 421.02, 628.58 and 396.45 is: 591.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.02 : 628.58 = 396.45 : x
  2. Step 2: Convert to fraction form
    421.02/628.58 = 396.45/x
  3. Step 3: Cross multiply
    421.02x = 628.58 × 396.45
  4. Step 4: Simplify right side
    421.02x = 249,201.53
  5. Step 5: Solve for x
    x = 249,201.53/421.02
  6. Step 6: Final answer
    x = 591.90

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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.