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Finding the Fourth Proportional to 621, 856.98 and 388.13

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Solution

The fourth proportional to 621, 856.98 and 388.13 is: 535.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    621 : 856.98 = 388.13 : x
  2. Step 2: Convert to fraction form
    621/856.98 = 388.13/x
  3. Step 3: Cross multiply
    621x = 856.98 × 388.13
  4. Step 4: Simplify right side
    621x = 332,615.36
  5. Step 5: Solve for x
    x = 332,615.36/621
  6. Step 6: Final answer
    x = 535.61

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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.