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Finding the Fourth Proportional to 1,238.48, 1,709.12 and 686.48

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Solution

The fourth proportional to 1,238.48, 1,709.12 and 686.48 is: 947.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,238.48 : 1,709.12 = 686.48 : x
  2. Step 2: Convert to fraction form
    1,238.48/1,709.12 = 686.48/x
  3. Step 3: Cross multiply
    1,238.48x = 1,709.12 × 686.48
  4. Step 4: Simplify right side
    1,238.48x = 1,173,276.70
  5. Step 5: Solve for x
    x = 1,173,276.70/1,238.48
  6. Step 6: Final answer
    x = 947.35

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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.