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Finding the Fourth Proportional to 783.84, 1,175.20 and 418.80

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Solution

The fourth proportional to 783.84, 1,175.20 and 418.80 is: 627.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.84 : 1,175.20 = 418.80 : x
  2. Step 2: Convert to fraction form
    783.84/1,175.20 = 418.80/x
  3. Step 3: Cross multiply
    783.84x = 1,175.20 × 418.80
  4. Step 4: Simplify right side
    783.84x = 492,173.76
  5. Step 5: Solve for x
    x = 492,173.76/783.84
  6. Step 6: Final answer
    x = 627.90

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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.