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Finding the Fourth Proportional to 1,281.58, 1,768.62 and 840.64

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Solution

The fourth proportional to 1,281.58, 1,768.62 and 840.64 is: 1,160.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,281.58 : 1,768.62 = 840.64 : x
  2. Step 2: Convert to fraction form
    1,281.58/1,768.62 = 840.64/x
  3. Step 3: Cross multiply
    1,281.58x = 1,768.62 × 840.64
  4. Step 4: Simplify right side
    1,281.58x = 1,486,772.72
  5. Step 5: Solve for x
    x = 1,486,772.72/1,281.58
  6. Step 6: Final answer
    x = 1,160.11

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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.