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Finding the Fourth Proportional to 840.72, 1,259.44 and 493.20

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Solution

The fourth proportional to 840.72, 1,259.44 and 493.20 is: 738.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.72 : 1,259.44 = 493.20 : x
  2. Step 2: Convert to fraction form
    840.72/1,259.44 = 493.20/x
  3. Step 3: Cross multiply
    840.72x = 1,259.44 × 493.20
  4. Step 4: Simplify right side
    840.72x = 621,155.81
  5. Step 5: Solve for x
    x = 621,155.81/840.72
  6. Step 6: Final answer
    x = 738.84

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Double scale
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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.