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Finding the Fourth Proportional to 390.76, 585.78 and 326.50

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Solution

The fourth proportional to 390.76, 585.78 and 326.50 is: 489.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.76 : 585.78 = 326.50 : x
  2. Step 2: Convert to fraction form
    390.76/585.78 = 326.50/x
  3. Step 3: Cross multiply
    390.76x = 585.78 × 326.50
  4. Step 4: Simplify right side
    390.76x = 191,257.17
  5. Step 5: Solve for x
    x = 191,257.17/390.76
  6. Step 6: Final answer
    x = 489.45

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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.