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Finding the Fourth Proportional to 866.40, 1,299.48 and 289.20

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Solution

The fourth proportional to 866.40, 1,299.48 and 289.20 is: 433.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    866.40 : 1,299.48 = 289.20 : x
  2. Step 2: Convert to fraction form
    866.40/1,299.48 = 289.20/x
  3. Step 3: Cross multiply
    866.40x = 1,299.48 × 289.20
  4. Step 4: Simplify right side
    866.40x = 375,809.62
  5. Step 5: Solve for x
    x = 375,809.62/866.40
  6. Step 6: Final answer
    x = 433.76

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Double scale
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Similar ratio
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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.