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Finding the Fourth Proportional to 840.42, 1,259.79 and 320.29

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Solution

The fourth proportional to 840.42, 1,259.79 and 320.29 is: 480.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.42 : 1,259.79 = 320.29 : x
  2. Step 2: Convert to fraction form
    840.42/1,259.79 = 320.29/x
  3. Step 3: Cross multiply
    840.42x = 1,259.79 × 320.29
  4. Step 4: Simplify right side
    840.42x = 403,498.14
  5. Step 5: Solve for x
    x = 403,498.14/840.42
  6. Step 6: Final answer
    x = 480.11

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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.