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Finding the Fourth Proportional to 810.20, 1,215.38 and 487.62

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Solution

The fourth proportional to 810.20, 1,215.38 and 487.62 is: 731.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.20 : 1,215.38 = 487.62 : x
  2. Step 2: Convert to fraction form
    810.20/1,215.38 = 487.62/x
  3. Step 3: Cross multiply
    810.20x = 1,215.38 × 487.62
  4. Step 4: Simplify right side
    810.20x = 592,638.12
  5. Step 5: Solve for x
    x = 592,638.12/810.20
  6. Step 6: Final answer
    x = 731.47

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Double scale
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1.5x scale

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.