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Finding the Fourth Proportional to 856.47, 1,174.22 and 840.90

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Solution

The fourth proportional to 856.47, 1,174.22 and 840.90 is: 1,152.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.47 : 1,174.22 = 840.90 : x
  2. Step 2: Convert to fraction form
    856.47/1,174.22 = 840.90/x
  3. Step 3: Cross multiply
    856.47x = 1,174.22 × 840.90
  4. Step 4: Simplify right side
    856.47x = 987,391.52
  5. Step 5: Solve for x
    x = 987,391.52/856.47
  6. Step 6: Final answer
    x = 1,152.87

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.