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Finding the Fourth Proportional to 620.90, 931.13 and 209.99

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Solution

The fourth proportional to 620.90, 931.13 and 209.99 is: 314.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.90 : 931.13 = 209.99 : x
  2. Step 2: Convert to fraction form
    620.90/931.13 = 209.99/x
  3. Step 3: Cross multiply
    620.90x = 931.13 × 209.99
  4. Step 4: Simplify right side
    620.90x = 195,530.05
  5. Step 5: Solve for x
    x = 195,530.05/620.90
  6. Step 6: Final answer
    x = 314.91

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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.