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Finding the Fourth Proportional to 1,078.85, 1,618.88 and 429.63

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Solution

The fourth proportional to 1,078.85, 1,618.88 and 429.63 is: 644.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,078.85 : 1,618.88 = 429.63 : x
  2. Step 2: Convert to fraction form
    1,078.85/1,618.88 = 429.63/x
  3. Step 3: Cross multiply
    1,078.85x = 1,618.88 × 429.63
  4. Step 4: Simplify right side
    1,078.85x = 695,517.27
  5. Step 5: Solve for x
    x = 695,517.27/1,078.85
  6. Step 6: Final answer
    x = 644.69

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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.