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Finding the Fourth Proportional to 840.15, 1,159.38 and 490.86

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Solution

The fourth proportional to 840.15, 1,159.38 and 490.86 is: 677.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.15 : 1,159.38 = 490.86 : x
  2. Step 2: Convert to fraction form
    840.15/1,159.38 = 490.86/x
  3. Step 3: Cross multiply
    840.15x = 1,159.38 × 490.86
  4. Step 4: Simplify right side
    840.15x = 569,093.27
  5. Step 5: Solve for x
    x = 569,093.27/840.15
  6. Step 6: Final answer
    x = 677.37

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Double scale
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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.