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Finding the Fourth Proportional to 897.20, 1,345.45 and 428.58

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Solution

The fourth proportional to 897.20, 1,345.45 and 428.58 is: 642.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    897.20 : 1,345.45 = 428.58 : x
  2. Step 2: Convert to fraction form
    897.20/1,345.45 = 428.58/x
  3. Step 3: Cross multiply
    897.20x = 1,345.45 × 428.58
  4. Step 4: Simplify right side
    897.20x = 576,639.62
  5. Step 5: Solve for x
    x = 576,639.62/897.20
  6. Step 6: Final answer
    x = 642.71

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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.