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Finding the Fourth Proportional to 855.48, 1,179.88 and 645.69

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Solution

The fourth proportional to 855.48, 1,179.88 and 645.69 is: 890.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.48 : 1,179.88 = 645.69 : x
  2. Step 2: Convert to fraction form
    855.48/1,179.88 = 645.69/x
  3. Step 3: Cross multiply
    855.48x = 1,179.88 × 645.69
  4. Step 4: Simplify right side
    855.48x = 761,836.72
  5. Step 5: Solve for x
    x = 761,836.72/855.48
  6. Step 6: Final answer
    x = 890.54

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Half scale
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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.