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Finding the Fourth Proportional to 839.89, 1,259.09 and 319.87

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Solution

The fourth proportional to 839.89, 1,259.09 and 319.87 is: 479.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.89 : 1,259.09 = 319.87 : x
  2. Step 2: Convert to fraction form
    839.89/1,259.09 = 319.87/x
  3. Step 3: Cross multiply
    839.89x = 1,259.09 × 319.87
  4. Step 4: Simplify right side
    839.89x = 402,745.12
  5. Step 5: Solve for x
    x = 402,745.12/839.89
  6. Step 6: Final answer
    x = 479.52

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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.