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Finding the Fourth Proportional to 520.48, 777.64 and 428.12

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Solution

The fourth proportional to 520.48, 777.64 and 428.12 is: 639.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.48 : 777.64 = 428.12 : x
  2. Step 2: Convert to fraction form
    520.48/777.64 = 428.12/x
  3. Step 3: Cross multiply
    520.48x = 777.64 × 428.12
  4. Step 4: Simplify right side
    520.48x = 332,923.24
  5. Step 5: Solve for x
    x = 332,923.24/520.48
  6. Step 6: Final answer
    x = 639.65

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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.