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Finding the Fourth Proportional to 639.35, 959.70 and 430.50

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Solution

The fourth proportional to 639.35, 959.70 and 430.50 is: 646.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.35 : 959.70 = 430.50 : x
  2. Step 2: Convert to fraction form
    639.35/959.70 = 430.50/x
  3. Step 3: Cross multiply
    639.35x = 959.70 × 430.50
  4. Step 4: Simplify right side
    639.35x = 413,150.85
  5. Step 5: Solve for x
    x = 413,150.85/639.35
  6. Step 6: Final answer
    x = 646.20

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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.