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Finding the Fourth Proportional to 840.50, 1,259.58 and 319.96

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Solution

The fourth proportional to 840.50, 1,259.58 and 319.96 is: 479.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.50 : 1,259.58 = 319.96 : x
  2. Step 2: Convert to fraction form
    840.50/1,259.58 = 319.96/x
  3. Step 3: Cross multiply
    840.50x = 1,259.58 × 319.96
  4. Step 4: Simplify right side
    840.50x = 403,015.22
  5. Step 5: Solve for x
    x = 403,015.22/840.50
  6. Step 6: Final answer
    x = 479.49

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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.