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Finding the Fourth Proportional to 491.76, 678.64 and 284.76

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Solution

The fourth proportional to 491.76, 678.64 and 284.76 is: 392.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.76 : 678.64 = 284.76 : x
  2. Step 2: Convert to fraction form
    491.76/678.64 = 284.76/x
  3. Step 3: Cross multiply
    491.76x = 678.64 × 284.76
  4. Step 4: Simplify right side
    491.76x = 193,249.53
  5. Step 5: Solve for x
    x = 193,249.53/491.76
  6. Step 6: Final answer
    x = 392.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.