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Finding the Fourth Proportional to 620.89, 856.64 and 385.01

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Solution

The fourth proportional to 620.89, 856.64 and 385.01 is: 531.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.89 : 856.64 = 385.01 : x
  2. Step 2: Convert to fraction form
    620.89/856.64 = 385.01/x
  3. Step 3: Cross multiply
    620.89x = 856.64 × 385.01
  4. Step 4: Simplify right side
    620.89x = 329,818.07
  5. Step 5: Solve for x
    x = 329,818.07/620.89
  6. Step 6: Final answer
    x = 531.20

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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.