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Finding the Fourth Proportional to 545.40, 817.20 and 399.60

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Solution

The fourth proportional to 545.40, 817.20 and 399.60 is: 598.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    545.40 : 817.20 = 399.60 : x
  2. Step 2: Convert to fraction form
    545.40/817.20 = 399.60/x
  3. Step 3: Cross multiply
    545.40x = 817.20 × 399.60
  4. Step 4: Simplify right side
    545.40x = 326,553.12
  5. Step 5: Solve for x
    x = 326,553.12/545.40
  6. Step 6: Final answer
    x = 598.74

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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.