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Finding the Fourth Proportional to 388.69, 583.20 and 145.15

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Solution

The fourth proportional to 388.69, 583.20 and 145.15 is: 217.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.69 : 583.20 = 145.15 : x
  2. Step 2: Convert to fraction form
    388.69/583.20 = 145.15/x
  3. Step 3: Cross multiply
    388.69x = 583.20 × 145.15
  4. Step 4: Simplify right side
    388.69x = 84,650.02
  5. Step 5: Solve for x
    x = 84,650.02/388.69
  6. Step 6: Final answer
    x = 217.78

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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.