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Finding the Fourth Proportional to 873.40, 1,205.40 and 542.20

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Solution

The fourth proportional to 873.40, 1,205.40 and 542.20 is: 748.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    873.40 : 1,205.40 = 542.20 : x
  2. Step 2: Convert to fraction form
    873.40/1,205.40 = 542.20/x
  3. Step 3: Cross multiply
    873.40x = 1,205.40 × 542.20
  4. Step 4: Simplify right side
    873.40x = 653,567.88
  5. Step 5: Solve for x
    x = 653,567.88/873.40
  6. Step 6: Final answer
    x = 748.30

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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.