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Finding the Fourth Proportional to 869.70, 1,200.54 and 630.78

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Solution

The fourth proportional to 869.70, 1,200.54 and 630.78 is: 870.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.70 : 1,200.54 = 630.78 : x
  2. Step 2: Convert to fraction form
    869.70/1,200.54 = 630.78/x
  3. Step 3: Cross multiply
    869.70x = 1,200.54 × 630.78
  4. Step 4: Simplify right side
    869.70x = 757,276.62
  5. Step 5: Solve for x
    x = 757,276.62/869.70
  6. Step 6: Final answer
    x = 870.73

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.