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Finding the Fourth Proportional to 491.70, 678.96 and 418.80

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Solution

The fourth proportional to 491.70, 678.96 and 418.80 is: 578.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.70 : 678.96 = 418.80 : x
  2. Step 2: Convert to fraction form
    491.70/678.96 = 418.80/x
  3. Step 3: Cross multiply
    491.70x = 678.96 × 418.80
  4. Step 4: Simplify right side
    491.70x = 284,348.45
  5. Step 5: Solve for x
    x = 284,348.45/491.70
  6. Step 6: Final answer
    x = 578.30

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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.