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Finding the Fourth Proportional to 816.78, 1,225.34 and 383.70

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Solution

The fourth proportional to 816.78, 1,225.34 and 383.70 is: 575.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.78 : 1,225.34 = 383.70 : x
  2. Step 2: Convert to fraction form
    816.78/1,225.34 = 383.70/x
  3. Step 3: Cross multiply
    816.78x = 1,225.34 × 383.70
  4. Step 4: Simplify right side
    816.78x = 470,162.96
  5. Step 5: Solve for x
    x = 470,162.96/816.78
  6. Step 6: Final answer
    x = 575.63

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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.