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Finding the Fourth Proportional to 288.64, 430.97 and 261.28

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Solution

The fourth proportional to 288.64, 430.97 and 261.28 is: 390.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.64 : 430.97 = 261.28 : x
  2. Step 2: Convert to fraction form
    288.64/430.97 = 261.28/x
  3. Step 3: Cross multiply
    288.64x = 430.97 × 261.28
  4. Step 4: Simplify right side
    288.64x = 112,603.84
  5. Step 5: Solve for x
    x = 112,603.84/288.64
  6. Step 6: Final answer
    x = 390.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.