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Finding the Fourth Proportional to 772.40, 1,158.28 and 285.12

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Solution

The fourth proportional to 772.40, 1,158.28 and 285.12 is: 427.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.40 : 1,158.28 = 285.12 : x
  2. Step 2: Convert to fraction form
    772.40/1,158.28 = 285.12/x
  3. Step 3: Cross multiply
    772.40x = 1,158.28 × 285.12
  4. Step 4: Simplify right side
    772.40x = 330,248.08
  5. Step 5: Solve for x
    x = 330,248.08/772.40
  6. Step 6: Final answer
    x = 427.56

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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.