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Finding the Fourth Proportional to 818.75, 1,129.70 and 487.29

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Solution

The fourth proportional to 818.75, 1,129.70 and 487.29 is: 672.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.75 : 1,129.70 = 487.29 : x
  2. Step 2: Convert to fraction form
    818.75/1,129.70 = 487.29/x
  3. Step 3: Cross multiply
    818.75x = 1,129.70 × 487.29
  4. Step 4: Simplify right side
    818.75x = 550,496.97
  5. Step 5: Solve for x
    x = 550,496.97/818.75
  6. Step 6: Final answer
    x = 672.36

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Half scale
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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.