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Finding the Fourth Proportional to 817.78, 1,223.61 and 487.51

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Solution

The fourth proportional to 817.78, 1,223.61 and 487.51 is: 729.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.78 : 1,223.61 = 487.51 : x
  2. Step 2: Convert to fraction form
    817.78/1,223.61 = 487.51/x
  3. Step 3: Cross multiply
    817.78x = 1,223.61 × 487.51
  4. Step 4: Simplify right side
    817.78x = 596,522.11
  5. Step 5: Solve for x
    x = 596,522.11/817.78
  6. Step 6: Final answer
    x = 729.44

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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.