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Finding the Fourth Proportional to 1,128.97, 1,557.38 and 686.57

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Solution

The fourth proportional to 1,128.97, 1,557.38 and 686.57 is: 947.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,128.97 : 1,557.38 = 686.57 : x
  2. Step 2: Convert to fraction form
    1,128.97/1,557.38 = 686.57/x
  3. Step 3: Cross multiply
    1,128.97x = 1,557.38 × 686.57
  4. Step 4: Simplify right side
    1,128.97x = 1,069,246.95
  5. Step 5: Solve for x
    x = 1,069,246.95/1,128.97
  6. Step 6: Final answer
    x = 947.10

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1.5x scale

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.