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Finding the Fourth Proportional to 1,245.61, 1,718.99 and 686.10

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Solution

The fourth proportional to 1,245.61, 1,718.99 and 686.10 is: 946.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,245.61 : 1,718.99 = 686.10 : x
  2. Step 2: Convert to fraction form
    1,245.61/1,718.99 = 686.10/x
  3. Step 3: Cross multiply
    1,245.61x = 1,718.99 × 686.10
  4. Step 4: Simplify right side
    1,245.61x = 1,179,399.04
  5. Step 5: Solve for x
    x = 1,179,399.04/1,245.61
  6. Step 6: Final answer
    x = 946.84

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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.