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Finding the Fourth Proportional to 856.55, 1,285.50 and 445.80

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Solution

The fourth proportional to 856.55, 1,285.50 and 445.80 is: 669.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.55 : 1,285.50 = 445.80 : x
  2. Step 2: Convert to fraction form
    856.55/1,285.50 = 445.80/x
  3. Step 3: Cross multiply
    856.55x = 1,285.50 × 445.80
  4. Step 4: Simplify right side
    856.55x = 573,082.39
  5. Step 5: Solve for x
    x = 573,082.39/856.55
  6. Step 6: Final answer
    x = 669.06

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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.