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Finding the Fourth Proportional to 620.64, 930.78 and 209.70

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Solution

The fourth proportional to 620.64, 930.78 and 209.70 is: 314.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.64 : 930.78 = 209.70 : x
  2. Step 2: Convert to fraction form
    620.64/930.78 = 209.70/x
  3. Step 3: Cross multiply
    620.64x = 930.78 × 209.70
  4. Step 4: Simplify right side
    620.64x = 195,184.57
  5. Step 5: Solve for x
    x = 195,184.57/620.64
  6. Step 6: Final answer
    x = 314.49

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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.