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Finding the Fourth Proportional to 864.72, 1,296.72 and 287.76

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Solution

The fourth proportional to 864.72, 1,296.72 and 287.76 is: 431.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.72 : 1,296.72 = 287.76 : x
  2. Step 2: Convert to fraction form
    864.72/1,296.72 = 287.76/x
  3. Step 3: Cross multiply
    864.72x = 1,296.72 × 287.76
  4. Step 4: Simplify right side
    864.72x = 373,144.15
  5. Step 5: Solve for x
    x = 373,144.15/864.72
  6. Step 6: Final answer
    x = 431.52

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1.5x scale

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.