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Finding the Fourth Proportional to 866.19, 1,299.63 and 378.90

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Solution

The fourth proportional to 866.19, 1,299.63 and 378.90 is: 568.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    866.19 : 1,299.63 = 378.90 : x
  2. Step 2: Convert to fraction form
    866.19/1,299.63 = 378.90/x
  3. Step 3: Cross multiply
    866.19x = 1,299.63 × 378.90
  4. Step 4: Simplify right side
    866.19x = 492,429.81
  5. Step 5: Solve for x
    x = 492,429.81/866.19
  6. Step 6: Final answer
    x = 568.50

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Double scale
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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.