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Finding the Fourth Proportional to 813.08, 1,123.80 and 638.12

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Solution

The fourth proportional to 813.08, 1,123.80 and 638.12 is: 881.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.08 : 1,123.80 = 638.12 : x
  2. Step 2: Convert to fraction form
    813.08/1,123.80 = 638.12/x
  3. Step 3: Cross multiply
    813.08x = 1,123.80 × 638.12
  4. Step 4: Simplify right side
    813.08x = 717,119.26
  5. Step 5: Solve for x
    x = 717,119.26/813.08
  6. Step 6: Final answer
    x = 881.98

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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.