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Finding the Fourth Proportional to 386.71, 579.65 and 261.63

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Solution

The fourth proportional to 386.71, 579.65 and 261.63 is: 392.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.71 : 579.65 = 261.63 : x
  2. Step 2: Convert to fraction form
    386.71/579.65 = 261.63/x
  3. Step 3: Cross multiply
    386.71x = 579.65 × 261.63
  4. Step 4: Simplify right side
    386.71x = 151,649.62
  5. Step 5: Solve for x
    x = 151,649.62/386.71
  6. Step 6: Final answer
    x = 392.16

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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.