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Finding the Fourth Proportional to 388.70, 581.70 and 267.20

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Solution

The fourth proportional to 388.70, 581.70 and 267.20 is: 399.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.70 : 581.70 = 267.20 : x
  2. Step 2: Convert to fraction form
    388.70/581.70 = 267.20/x
  3. Step 3: Cross multiply
    388.70x = 581.70 × 267.20
  4. Step 4: Simplify right side
    388.70x = 155,430.24
  5. Step 5: Solve for x
    x = 155,430.24/388.70
  6. Step 6: Final answer
    x = 399.87

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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.