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Finding the Fourth Proportional to 611.20, 916.80 and 416.80

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Solution

The fourth proportional to 611.20, 916.80 and 416.80 is: 625.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.20 : 916.80 = 416.80 : x
  2. Step 2: Convert to fraction form
    611.20/916.80 = 416.80/x
  3. Step 3: Cross multiply
    611.20x = 916.80 × 416.80
  4. Step 4: Simplify right side
    611.20x = 382,122.24
  5. Step 5: Solve for x
    x = 382,122.24/611.20
  6. Step 6: Final answer
    x = 625.20

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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.