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Finding the Fourth Proportional to 1,128.95, 1,558.08 and 686.91

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Solution

The fourth proportional to 1,128.95, 1,558.08 and 686.91 is: 948.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,128.95 : 1,558.08 = 686.91 : x
  2. Step 2: Convert to fraction form
    1,128.95/1,558.08 = 686.91/x
  3. Step 3: Cross multiply
    1,128.95x = 1,558.08 × 686.91
  4. Step 4: Simplify right side
    1,128.95x = 1,070,260.73
  5. Step 5: Solve for x
    x = 1,070,260.73/1,128.95
  6. Step 6: Final answer
    x = 948.02

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.