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Finding the Fourth Proportional to 813.92, 1,123.70 and 646.55

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Solution

The fourth proportional to 813.92, 1,123.70 and 646.55 is: 892.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.92 : 1,123.70 = 646.55 : x
  2. Step 2: Convert to fraction form
    813.92/1,123.70 = 646.55/x
  3. Step 3: Cross multiply
    813.92x = 1,123.70 × 646.55
  4. Step 4: Simplify right side
    813.92x = 726,519.38
  5. Step 5: Solve for x
    x = 726,519.38/813.92
  6. Step 6: Final answer
    x = 892.62

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Double scale
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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.