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Finding the Fourth Proportional to 997.60, 1,375.44 and 642.90

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Solution

The fourth proportional to 997.60, 1,375.44 and 642.90 is: 886.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    997.60 : 1,375.44 = 642.90 : x
  2. Step 2: Convert to fraction form
    997.60/1,375.44 = 642.90/x
  3. Step 3: Cross multiply
    997.60x = 1,375.44 × 642.90
  4. Step 4: Simplify right side
    997.60x = 884,270.38
  5. Step 5: Solve for x
    x = 884,270.38/997.60
  6. Step 6: Final answer
    x = 886.40

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.