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Finding the Fourth Proportional to 856.20, 1,283.71 and 438.71

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Solution

The fourth proportional to 856.20, 1,283.71 and 438.71 is: 657.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.20 : 1,283.71 = 438.71 : x
  2. Step 2: Convert to fraction form
    856.20/1,283.71 = 438.71/x
  3. Step 3: Cross multiply
    856.20x = 1,283.71 × 438.71
  4. Step 4: Simplify right side
    856.20x = 563,174.22
  5. Step 5: Solve for x
    x = 563,174.22/856.20
  6. Step 6: Final answer
    x = 657.76

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Double scale
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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.