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Finding the Fourth Proportional to 840.24, 1,257.62 and 620.76

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Solution

The fourth proportional to 840.24, 1,257.62 and 620.76 is: 929.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.24 : 1,257.62 = 620.76 : x
  2. Step 2: Convert to fraction form
    840.24/1,257.62 = 620.76/x
  3. Step 3: Cross multiply
    840.24x = 1,257.62 × 620.76
  4. Step 4: Simplify right side
    840.24x = 780,680.19
  5. Step 5: Solve for x
    x = 780,680.19/840.24
  6. Step 6: Final answer
    x = 929.12

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1.5x scale

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.