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Finding the Fourth Proportional to 661.72, 992.64 and 387.84

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Solution

The fourth proportional to 661.72, 992.64 and 387.84 is: 581.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.72 : 992.64 = 387.84 : x
  2. Step 2: Convert to fraction form
    661.72/992.64 = 387.84/x
  3. Step 3: Cross multiply
    661.72x = 992.64 × 387.84
  4. Step 4: Simplify right side
    661.72x = 384,985.50
  5. Step 5: Solve for x
    x = 384,985.50/661.72
  6. Step 6: Final answer
    x = 581.80

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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.