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Finding the Fourth Proportional to 761.76, 1,142.40 and 328.64

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Solution

The fourth proportional to 761.76, 1,142.40 and 328.64 is: 492.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    761.76 : 1,142.40 = 328.64 : x
  2. Step 2: Convert to fraction form
    761.76/1,142.40 = 328.64/x
  3. Step 3: Cross multiply
    761.76x = 1,142.40 × 328.64
  4. Step 4: Simplify right side
    761.76x = 375,438.34
  5. Step 5: Solve for x
    x = 375,438.34/761.76
  6. Step 6: Final answer
    x = 492.86

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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.