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Finding the Fourth Proportional to 661.50, 992.61 and 319.50

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Solution

The fourth proportional to 661.50, 992.61 and 319.50 is: 479.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.50 : 992.61 = 319.50 : x
  2. Step 2: Convert to fraction form
    661.50/992.61 = 319.50/x
  3. Step 3: Cross multiply
    661.50x = 992.61 × 319.50
  4. Step 4: Simplify right side
    661.50x = 317,138.90
  5. Step 5: Solve for x
    x = 317,138.90/661.50
  6. Step 6: Final answer
    x = 479.42

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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.