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Finding the Fourth Proportional to 387.42, 581.34 and 386.21

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Solution

The fourth proportional to 387.42, 581.34 and 386.21 is: 579.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.42 : 581.34 = 386.21 : x
  2. Step 2: Convert to fraction form
    387.42/581.34 = 386.21/x
  3. Step 3: Cross multiply
    387.42x = 581.34 × 386.21
  4. Step 4: Simplify right side
    387.42x = 224,516.41
  5. Step 5: Solve for x
    x = 224,516.41/387.42
  6. Step 6: Final answer
    x = 579.52

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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.