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Finding the Fourth Proportional to 669.99, 1,005.35 and 639.03

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Solution

The fourth proportional to 669.99, 1,005.35 and 639.03 is: 958.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.99 : 1,005.35 = 639.03 : x
  2. Step 2: Convert to fraction form
    669.99/1,005.35 = 639.03/x
  3. Step 3: Cross multiply
    669.99x = 1,005.35 × 639.03
  4. Step 4: Simplify right side
    669.99x = 642,445.62
  5. Step 5: Solve for x
    x = 642,445.62/669.99
  6. Step 6: Final answer
    x = 958.89

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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.