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Finding the Fourth Proportional to 621.65, 856.90 and 503.80

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Solution

The fourth proportional to 621.65, 856.90 and 503.80 is: 694.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.65 : 856.90 = 503.80 : x
  2. Step 2: Convert to fraction form
    621.65/856.90 = 503.80/x
  3. Step 3: Cross multiply
    621.65x = 856.90 × 503.80
  4. Step 4: Simplify right side
    621.65x = 431,706.22
  5. Step 5: Solve for x
    x = 431,706.22/621.65
  6. Step 6: Final answer
    x = 694.45

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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.