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Finding the Fourth Proportional to 640.58, 961.76 and 328.45

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Solution

The fourth proportional to 640.58, 961.76 and 328.45 is: 493.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.58 : 961.76 = 328.45 : x
  2. Step 2: Convert to fraction form
    640.58/961.76 = 328.45/x
  3. Step 3: Cross multiply
    640.58x = 961.76 × 328.45
  4. Step 4: Simplify right side
    640.58x = 315,890.07
  5. Step 5: Solve for x
    x = 315,890.07/640.58
  6. Step 6: Final answer
    x = 493.13

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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.