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Finding the Fourth Proportional to 840.12, 1,159.12 and 490.80

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Solution

The fourth proportional to 840.12, 1,159.12 and 490.80 is: 677.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.12 : 1,159.12 = 490.80 : x
  2. Step 2: Convert to fraction form
    840.12/1,159.12 = 490.80/x
  3. Step 3: Cross multiply
    840.12x = 1,159.12 × 490.80
  4. Step 4: Simplify right side
    840.12x = 568,896.10
  5. Step 5: Solve for x
    x = 568,896.10/840.12
  6. Step 6: Final answer
    x = 677.16

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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.