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Finding the Fourth Proportional to 666.70, 918.61 and 621.54

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Solution

The fourth proportional to 666.70, 918.61 and 621.54 is: 856.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.70 : 918.61 = 621.54 : x
  2. Step 2: Convert to fraction form
    666.70/918.61 = 621.54/x
  3. Step 3: Cross multiply
    666.70x = 918.61 × 621.54
  4. Step 4: Simplify right side
    666.70x = 570,951.31
  5. Step 5: Solve for x
    x = 570,951.31/666.70
  6. Step 6: Final answer
    x = 856.39

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Double scale
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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.