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Finding the Fourth Proportional to 738.78, 1,019.64 and 428.28

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Solution

The fourth proportional to 738.78, 1,019.64 and 428.28 is: 591.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    738.78 : 1,019.64 = 428.28 : x
  2. Step 2: Convert to fraction form
    738.78/1,019.64 = 428.28/x
  3. Step 3: Cross multiply
    738.78x = 1,019.64 × 428.28
  4. Step 4: Simplify right side
    738.78x = 436,691.42
  5. Step 5: Solve for x
    x = 436,691.42/738.78
  6. Step 6: Final answer
    x = 591.10

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1.5x scale

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.