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Finding the Fourth Proportional to 691.61, 1,037.21 and 258.66

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Solution

The fourth proportional to 691.61, 1,037.21 and 258.66 is: 387.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.61 : 1,037.21 = 258.66 : x
  2. Step 2: Convert to fraction form
    691.61/1,037.21 = 258.66/x
  3. Step 3: Cross multiply
    691.61x = 1,037.21 × 258.66
  4. Step 4: Simplify right side
    691.61x = 268,283.45
  5. Step 5: Solve for x
    x = 268,283.45/691.61
  6. Step 6: Final answer
    x = 387.91

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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.