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Finding the Fourth Proportional to 871.80, 1,307.20 and 409.88

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Solution

The fourth proportional to 871.80, 1,307.20 and 409.88 is: 614.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.80 : 1,307.20 = 409.88 : x
  2. Step 2: Convert to fraction form
    871.80/1,307.20 = 409.88/x
  3. Step 3: Cross multiply
    871.80x = 1,307.20 × 409.88
  4. Step 4: Simplify right side
    871.80x = 535,795.14
  5. Step 5: Solve for x
    x = 535,795.14/871.80
  6. Step 6: Final answer
    x = 614.58

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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.