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Finding the Fourth Proportional to 289.28, 431.66 and 258.51

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Solution

The fourth proportional to 289.28, 431.66 and 258.51 is: 385.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.28 : 431.66 = 258.51 : x
  2. Step 2: Convert to fraction form
    289.28/431.66 = 258.51/x
  3. Step 3: Cross multiply
    289.28x = 431.66 × 258.51
  4. Step 4: Simplify right side
    289.28x = 111,587.13
  5. Step 5: Solve for x
    x = 111,587.13/289.28
  6. Step 6: Final answer
    x = 385.75

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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.