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Finding the Fourth Proportional to 449.55, 669.87 and 428.90

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Solution

The fourth proportional to 449.55, 669.87 and 428.90 is: 639.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    449.55 : 669.87 = 428.90 : x
  2. Step 2: Convert to fraction form
    449.55/669.87 = 428.90/x
  3. Step 3: Cross multiply
    449.55x = 669.87 × 428.90
  4. Step 4: Simplify right side
    449.55x = 287,303.89
  5. Step 5: Solve for x
    x = 287,303.89/449.55
  6. Step 6: Final answer
    x = 639.09

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.