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Finding the Fourth Proportional to 620.90, 856.77 and 384.78

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Solution

The fourth proportional to 620.90, 856.77 and 384.78 is: 530.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.90 : 856.77 = 384.78 : x
  2. Step 2: Convert to fraction form
    620.90/856.77 = 384.78/x
  3. Step 3: Cross multiply
    620.90x = 856.77 × 384.78
  4. Step 4: Simplify right side
    620.90x = 329,667.96
  5. Step 5: Solve for x
    x = 329,667.96/620.90
  6. Step 6: Final answer
    x = 530.96

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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.