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Finding the Fourth Proportional to 387.21, 580.77 and 98.64

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Solution

The fourth proportional to 387.21, 580.77 and 98.64 is: 147.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.21 : 580.77 = 98.64 : x
  2. Step 2: Convert to fraction form
    387.21/580.77 = 98.64/x
  3. Step 3: Cross multiply
    387.21x = 580.77 × 98.64
  4. Step 4: Simplify right side
    387.21x = 57,287.15
  5. Step 5: Solve for x
    x = 57,287.15/387.21
  6. Step 6: Final answer
    x = 147.95

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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.