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Finding the Fourth Proportional to 671.85, 1,005.71 and 615.15

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Solution

The fourth proportional to 671.85, 1,005.71 and 615.15 is: 920.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    671.85 : 1,005.71 = 615.15 : x
  2. Step 2: Convert to fraction form
    671.85/1,005.71 = 615.15/x
  3. Step 3: Cross multiply
    671.85x = 1,005.71 × 615.15
  4. Step 4: Simplify right side
    671.85x = 618,662.51
  5. Step 5: Solve for x
    x = 618,662.51/671.85
  6. Step 6: Final answer
    x = 920.83

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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.