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Finding the Fourth Proportional to 421.38, 578.10 and 400.71

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Solution

The fourth proportional to 421.38, 578.10 and 400.71 is: 549.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.38 : 578.10 = 400.71 : x
  2. Step 2: Convert to fraction form
    421.38/578.10 = 400.71/x
  3. Step 3: Cross multiply
    421.38x = 578.10 × 400.71
  4. Step 4: Simplify right side
    421.38x = 231,650.45
  5. Step 5: Solve for x
    x = 231,650.45/421.38
  6. Step 6: Final answer
    x = 549.74

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.