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Finding the Fourth Proportional to 840.42, 1,259.73 and 429.17

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Solution

The fourth proportional to 840.42, 1,259.73 and 429.17 is: 643.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.42 : 1,259.73 = 429.17 : x
  2. Step 2: Convert to fraction form
    840.42/1,259.73 = 429.17/x
  3. Step 3: Cross multiply
    840.42x = 1,259.73 × 429.17
  4. Step 4: Simplify right side
    840.42x = 540,632.03
  5. Step 5: Solve for x
    x = 540,632.03/840.42
  6. Step 6: Final answer
    x = 643.29

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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.