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Finding the Fourth Proportional to 418.40, 627.78 and 187.45

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Solution

The fourth proportional to 418.40, 627.78 and 187.45 is: 281.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.40 : 627.78 = 187.45 : x
  2. Step 2: Convert to fraction form
    418.40/627.78 = 187.45/x
  3. Step 3: Cross multiply
    418.40x = 627.78 × 187.45
  4. Step 4: Simplify right side
    418.40x = 117,676.49
  5. Step 5: Solve for x
    x = 117,676.49/418.40
  6. Step 6: Final answer
    x = 281.25

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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.