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Finding the Fourth Proportional to 1,318.32, 1,978.62 and 538.74

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Solution

The fourth proportional to 1,318.32, 1,978.62 and 538.74 is: 808.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,318.32 : 1,978.62 = 538.74 : x
  2. Step 2: Convert to fraction form
    1,318.32/1,978.62 = 538.74/x
  3. Step 3: Cross multiply
    1,318.32x = 1,978.62 × 538.74
  4. Step 4: Simplify right side
    1,318.32x = 1,065,961.74
  5. Step 5: Solve for x
    x = 1,065,961.74/1,318.32
  6. Step 6: Final answer
    x = 808.58

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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.