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Finding the Fourth Proportional to 388.40, 581.52 and 319.28

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Solution

The fourth proportional to 388.40, 581.52 and 319.28 is: 478.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.40 : 581.52 = 319.28 : x
  2. Step 2: Convert to fraction form
    388.40/581.52 = 319.28/x
  3. Step 3: Cross multiply
    388.40x = 581.52 × 319.28
  4. Step 4: Simplify right side
    388.40x = 185,667.71
  5. Step 5: Solve for x
    x = 185,667.71/388.40
  6. Step 6: Final answer
    x = 478.03

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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.