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Finding the Fourth Proportional to 1,245.88, 1,719.32 and 686.40

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Solution

The fourth proportional to 1,245.88, 1,719.32 and 686.40 is: 947.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,245.88 : 1,719.32 = 686.40 : x
  2. Step 2: Convert to fraction form
    1,245.88/1,719.32 = 686.40/x
  3. Step 3: Cross multiply
    1,245.88x = 1,719.32 × 686.40
  4. Step 4: Simplify right side
    1,245.88x = 1,180,141.25
  5. Step 5: Solve for x
    x = 1,180,141.25/1,245.88
  6. Step 6: Final answer
    x = 947.24

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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.