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Finding the Fourth Proportional to 666.50, 999.88 and 392.78

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Solution

The fourth proportional to 666.50, 999.88 and 392.78 is: 589.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.50 : 999.88 = 392.78 : x
  2. Step 2: Convert to fraction form
    666.50/999.88 = 392.78/x
  3. Step 3: Cross multiply
    666.50x = 999.88 × 392.78
  4. Step 4: Simplify right side
    666.50x = 392,734.38
  5. Step 5: Solve for x
    x = 392,734.38/666.50
  6. Step 6: Final answer
    x = 589.25

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1.5x scale

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.