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Finding the Fourth Proportional to 688.10, 949.86 and 621.41

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Solution

The fourth proportional to 688.10, 949.86 and 621.41 is: 857.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.10 : 949.86 = 621.41 : x
  2. Step 2: Convert to fraction form
    688.10/949.86 = 621.41/x
  3. Step 3: Cross multiply
    688.10x = 949.86 × 621.41
  4. Step 4: Simplify right side
    688.10x = 590,247.75
  5. Step 5: Solve for x
    x = 590,247.75/688.10
  6. Step 6: Final answer
    x = 857.80

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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.