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Finding the Fourth Proportional to 899.28, 1,238.52 and 840.72

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Solution

The fourth proportional to 899.28, 1,238.52 and 840.72 is: 1,157.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    899.28 : 1,238.52 = 840.72 : x
  2. Step 2: Convert to fraction form
    899.28/1,238.52 = 840.72/x
  3. Step 3: Cross multiply
    899.28x = 1,238.52 × 840.72
  4. Step 4: Simplify right side
    899.28x = 1,041,248.53
  5. Step 5: Solve for x
    x = 1,041,248.53/899.28
  6. Step 6: Final answer
    x = 1,157.87

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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.