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Finding the Fourth Proportional to 1,292.40, 1,783.80 and 998.28

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Solution

The fourth proportional to 1,292.40, 1,783.80 and 998.28 is: 1,377.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,292.40 : 1,783.80 = 998.28 : x
  2. Step 2: Convert to fraction form
    1,292.40/1,783.80 = 998.28/x
  3. Step 3: Cross multiply
    1,292.40x = 1,783.80 × 998.28
  4. Step 4: Simplify right side
    1,292.40x = 1,780,731.86
  5. Step 5: Solve for x
    x = 1,780,731.86/1,292.40
  6. Step 6: Final answer
    x = 1,377.85

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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.