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Finding the Fourth Proportional to 388.80, 545.40 and 388.80

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Solution

The fourth proportional to 388.80, 545.40 and 388.80 is: 545.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.80 : 545.40 = 388.80 : x
  2. Step 2: Convert to fraction form
    388.80/545.40 = 388.80/x
  3. Step 3: Cross multiply
    388.80x = 545.40 × 388.80
  4. Step 4: Simplify right side
    388.80x = 212,051.52
  5. Step 5: Solve for x
    x = 212,051.52/388.80
  6. Step 6: Final answer
    x = 545.40

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.