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Finding the Fourth Proportional to 920.72, 1,381.12 and 458.72

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Solution

The fourth proportional to 920.72, 1,381.12 and 458.72 is: 688.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.72 : 1,381.12 = 458.72 : x
  2. Step 2: Convert to fraction form
    920.72/1,381.12 = 458.72/x
  3. Step 3: Cross multiply
    920.72x = 1,381.12 × 458.72
  4. Step 4: Simplify right side
    920.72x = 633,547.37
  5. Step 5: Solve for x
    x = 633,547.37/920.72
  6. Step 6: Final answer
    x = 688.10

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Half scale
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Double scale
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Similar ratio
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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.