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Finding the Fourth Proportional to 1,239.32, 1,710.24 and 679.80

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Solution

The fourth proportional to 1,239.32, 1,710.24 and 679.80 is: 938.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.32 : 1,710.24 = 679.80 : x
  2. Step 2: Convert to fraction form
    1,239.32/1,710.24 = 679.80/x
  3. Step 3: Cross multiply
    1,239.32x = 1,710.24 × 679.80
  4. Step 4: Simplify right side
    1,239.32x = 1,162,621.15
  5. Step 5: Solve for x
    x = 1,162,621.15/1,239.32
  6. Step 6: Final answer
    x = 938.11

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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.