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Finding the Fourth Proportional to 840.64, 1,159.68 and 724

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Solution

The fourth proportional to 840.64, 1,159.68 and 724 is: 998.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.64 : 1,159.68 = 724 : x
  2. Step 2: Convert to fraction form
    840.64/1,159.68 = 724/x
  3. Step 3: Cross multiply
    840.64x = 1,159.68 × 724
  4. Step 4: Simplify right side
    840.64x = 839,608.32
  5. Step 5: Solve for x
    x = 839,608.32/840.64
  6. Step 6: Final answer
    x = 998.77

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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.