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Finding the Fourth Proportional to 620.70, 931.10 and 209.86

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Solution

The fourth proportional to 620.70, 931.10 and 209.86 is: 314.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.70 : 931.10 = 209.86 : x
  2. Step 2: Convert to fraction form
    620.70/931.10 = 209.86/x
  3. Step 3: Cross multiply
    620.70x = 931.10 × 209.86
  4. Step 4: Simplify right side
    620.70x = 195,397.27
  5. Step 5: Solve for x
    x = 195,397.27/620.70
  6. Step 6: Final answer
    x = 314.80

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.