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Finding the Fourth Proportional to 1,285.10, 1,773.71 and 812.70

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Solution

The fourth proportional to 1,285.10, 1,773.71 and 812.70 is: 1,121.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.10 : 1,773.71 = 812.70 : x
  2. Step 2: Convert to fraction form
    1,285.10/1,773.71 = 812.70/x
  3. Step 3: Cross multiply
    1,285.10x = 1,773.71 × 812.70
  4. Step 4: Simplify right side
    1,285.10x = 1,441,490.05
  5. Step 5: Solve for x
    x = 1,441,490.05/1,285.10
  6. Step 6: Final answer
    x = 1,121.70

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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.