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Finding the Fourth Proportional to 319.90, 479.88 and 103.40

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Solution

The fourth proportional to 319.90, 479.88 and 103.40 is: 155.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.90 : 479.88 = 103.40 : x
  2. Step 2: Convert to fraction form
    319.90/479.88 = 103.40/x
  3. Step 3: Cross multiply
    319.90x = 479.88 × 103.40
  4. Step 4: Simplify right side
    319.90x = 49,619.59
  5. Step 5: Solve for x
    x = 49,619.59/319.90
  6. Step 6: Final answer
    x = 155.11

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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.