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Finding the Fourth Proportional to 645.95, 891.06 and 383.78

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Solution

The fourth proportional to 645.95, 891.06 and 383.78 is: 529.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.95 : 891.06 = 383.78 : x
  2. Step 2: Convert to fraction form
    645.95/891.06 = 383.78/x
  3. Step 3: Cross multiply
    645.95x = 891.06 × 383.78
  4. Step 4: Simplify right side
    645.95x = 341,971.01
  5. Step 5: Solve for x
    x = 341,971.01/645.95
  6. Step 6: Final answer
    x = 529.41

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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.